CathInfo.com

What about Franciscans who wear sandals? Are they immodest if parts of the feet are seen? 
I’m all for modesty, in both sexes, especially, though, for women.
This can also be taken too far, for example, if Catholics adopted full Muslim dress for women and men, the matter would be solved, right?
Or if all Catholics moved above the Arctic or below the Antarctic circles and lived in igloos, we’d be covered head to toe at all times.
One does need to look at docuмents such as the Marylike standards in the context they were given, originally a letter to religious sisters who were allowing the girls and young women in their schools and organizations to become lax in modesty. It was not a papal encyclical binding on the entire Church.  In 1928, the year of its origin, floor or street length dresses, full, opaque stockings, sleeves covering the elbows and tops that showed no neck were not the norm among decent society. Remember what came before 1928, Flapper girls and their Sheiks. Those styles were and are still are grossly immodest! The men may have been covered, but the suits were so extreme as to make the ladies look. Actually, they looked ridiculous if not immodest. Trying to be singular by one’s dress, even if it is modest, is a form of immodesty itself. Pride says, “Hey, everyone, look at me! Admire my great modesty!”

What I’m saying is that Catholics should take the Mary-like Standards as guidelines rather than specific clothing rules to be followed to the letter. They were not written as such. They were addressing immodesty issues of that time and place, and speaking specifically to certain problems.
If written today by a true Pope, there would be many more prohibitions and would have to include men and boys, not just females. It’s 2026, so we can no longer follow Bp. Williamson’s instructions to dress and do as grandma.  Lots of today’s grandmas were letting it all hang out at Woodstock, wore bikinis and hot pants. We have to go back to great grandparents, and how many young people knew them much less how they dressed and what they did? 
Being older, I still can recall my grandparents. All four of them were born in the period between 1897 and 1906. There are lots of old photos, even a few from their childhoods. All four were considered well-dressed although neither grandmother wore floor length skirts. Young girls did not wear floor length dresses in the late 1800’s, early 1900’s, although women did up until WWI. Both grandma’s fashions kind of stopped changing so far as modesty in about 1950. One grandfather, I don’t know as he abandoned ship. The other always wore pants, and a golf shirt for casual wear. I never saw him in shorts. As a young married man, he wore knickers with argyle socks for casual wear! My Dad wore knickers until he was about 10 when he got his first big boy pants. There’s a picture of Dad’s First Communion in which all the boys are wearing white suits and ties, but with middle of the knee-length loose-fitting shorts. Yes, there’s bare leg showing. 😮 The girls are all also dressed alike in very fancy white dresses that hung a little above the ankle. They have on white stockings and white ghilly laced shoes, and of course, long veils with a satin band with flowers at the edges. The photo was taken in May of 1929. The priests were in black cassocks and nuns in full habits. It’s kind of hard to tell, but I believe they were Dominicans. 

Good explanation.

I think Maria and Anthony have already answered well, and I am certainly no theologian. I'm a traditionalist. As Bishop Williamson used to say to the girls when preaching against pants, find a way to do it how your grandmother did it, and if your grandmother didn't do it, forget it.

There are two broad considerations, as I see it, that need to be considered with your proposed new fashion:
1. The psychological effect it has on the woman wearing it, just as Bishop de Castro Mayer, Bishop Williamson and others argued with regards women wearing pants.
2. The incitement to concupiscence in men.

With regards the second especially, the basic principle is that modest dress seeks to conceal, rather than reveal, both flesh and form.

Now with your proposed dress, clearly more of the form is being revealed, and that in a crucial area. How far up can the dress be taken before it becomes sinful? How is modesty preserved when seated?

Returning to the original post, it is clear to me that the Pope is forbidding BOTH dresses that don't come below the knee AND flesh coloured leggings/stockings. Not only is that the obvious reading of the letter but I would understand it that way, if for no other reason, because that is how Christian women once dressed - dress below the knee, and legs concealed, and these were the two revolutionary fashions creeping in - shorter dresses and skirts, and flesh-coloured leggings. Even when I was a youngster in the seventies, this is how the older ladies dressed. I remember how horrified I was when some of the young ladies started turning up with bare legs and open 'shoes'. How times change in our modern liberal world, and it affects us and our judgments whether we believe it or not. If Catholic women dressed this way for 2000 years, it's not because they lacked imagination when it comes to fashion.

Finally, on the topic of modesty, here is a little inspiring passage from "The Father of the Little Flower" by his daughter Celine:
"He would never tolerate, either for himself or for anyone else in the house, a careless appearance, or any lack of modesty in dress. We should not have dared, in his presence, to have had short-sleeved dresses, only just to the elbow. What would he say of the world today?"

How far we have come from the Catholic ideal.

You start well by laying out the principles, and one need not be a "theologian", as this really has little to do with theology, but simply applying reason.

Indeed, there two primary principles involved ...

1) inducement to concupiscence
2) appearing and behaving in a manner that's contrary to nature

Now, there can be other principles, such as

... not being a slob, therefore maintaining the dignity of the body as the temple of the Holy Ghost.  I believe that's a great vice today, with people dressing like slobs everywhere, even if not immodestly ... and that's militates against the dignity of man, created in the image and likeness of God
... not being vain (you can actually dress TOO fancy, so while not immodest or not contrary to nature, if you dress ostentatiously so as to draw attention to yourself)
... not flaunting your wealth and possibly causing scandal (if people see you wearing very expensive clothing while there are poor people who might need help)
... causing scandal and disedification regarding any of the above principles, so this one is derivative of the others

But, despite these secondary considerations that are more venial in nature, though nevertheless to be avoided, behaving/appearing contrary to nature and inducing others to concupiscence are in fact the two primary principles.

So now one applies the principles.  Those two examples do not incide to concupiscence (if you disregard the elements I blotted out), nor are they unfemine, though the one on the right, one might make a case for being less than ideal in that area.

Those examples are not fashions that were prevalent at the time of "Padre Pio", who was absurdly name-dropped, without any substantiation.  I could go on forever about using Padre Pio as some "rule of faith", since not only has there never been more apocryphal material and "sayings" attributed to anyone in history more than to Padre Pio, but we go by what the Church holds and not Padre Pio.  Padre Pio had his reasons, and there were points he was making, sometimes under God's inspiration, but at other times based on his own judgment.

So, given that Padre Pio was a sensational character due to the preternatural phenomena associated with him and then combine that with the fact that many who had known him were still alive when the "internet era" began, that was the perfect storm which led to this mountain of fakery attributed to Padre Pio.  If you added up all those who claimed to have been "spiritual daughters" of Padre Pio, the vast majority of whom maybe went to him for Confession a single time and based on that arrogated the title unto themselves ... if you add up all the claimants, you'd likely be in the tens of thousands.  Then you add to it that people walked out of Confession relating stories about what Padre ALLEGEDLY said to them, out of context, possibly misunderstanding, misremembering, perhaps taking something that was specific to them and extrapolating that into some general "teaching" of Padre Pio, etc. etc. etc.  Padre Pio wasn't infallible either, as there were a number of cases where people asked him about various situations and he was incorrect in his judgment about what was taking place.  Padre Pio had preternatural knowledge of things only to the extent that God chose to reveal them to Him, but God did not render him either omniscient or infallible.  Even Padre Pio's REPORTED insistence that women wear dresses/skirts that were 8 inches below the knee had some context around it.  Evidently there were women who tried to do the bare minimum required, and played games like arriving in shorter skirts and then stretching them down at the last second to get buy those who are stationed outside to make sure they were modest, i.e. trying to get away with things and pull the wool over people's eyes, and Padre Pio reacted to that by insisting upon a requirement that they couldn't fake their way through.  But the standards from the Holy Office simply stated that the dresses/skirts should not just barely be below the knee, and one might interpret that to mean that it's not a situation where it's so borderline that the knee might show depending upon a woman's gait or a slight breeze or sitting down in the pew, namely, that it should be long enough that there's not question that in nearly all circuмstances the knees would remain covered.

Back to the Holy Office's standards regarding the flesh-colored stockings, no, absolutely not.  I have no idea what you're reading, but it's absurd to read the Pope's teaching the way you claim.  So it's OK for women to have bare legs beneath an appropriately long dress, but not to wear stockings that ... make their legs appear ... bare?  That's just ridiculous.  If bare legs are permitted, then so are stockings that ... make the legs appear wear.  That's just nonsense, and I have never seen ANY interpretation of the standards that would require a ban on all stockings / pantyhose that are flesh-colored, provided the OTHER criteria are met.  Clearly what's being explained is a situation where you have a combination of a short skirt with stockings, but the stockings make it appear that the legs are exposed beneath a short skirt.  And it's in line with the explanation about see-through skirts, where it's a combination of factors, i.e. where not only must the skirt be long enough, but even if it's long enough, it mean snothing if you can see through the parts that are covering the areas that should be covered.  It's quite obvious what is mean.  So, for instance, a woman might say, but this skirt meets the standards since it goes well below the knees, but then you could see through it (meaning partially ... they're obviously not talking about completely see-through skirts, but situations where you can even partially see through it).  Similarly, if a woman had a shorter skirt but combined it with stockings, if they were thicker and disguised the look of below the shorter skirt so that it did not in conjunction yield a "look" that was the equivalent of seeing a woman in a mini-skirt.

But, if a woman wore something like the pictures I posted, it does not violate the standards.  Now, they would be inappropriate for Mass, since ... it's rather undignified for Mass, too casual ... kindof like if a man might wear jeans that might not be otherwise immodest, or some overalls, etc.  Not immodest, but inappropriate to do making you look like a slob at Mass.  But if women wore such as those in more casual situations, then I find absolutely nothing wrong with those ensembles, since ... and we circle back to the beginning, they do not violate either of the two prime principles, i.e. they do not look masculine (if some man wore those outfits you'd be repulsed by obvious transvestism) nor are they inducements to concupiscence, since the legs are covereed by pant legs.

It's not so simple today in the re-paganized world. 
I did not grow up as a traditional Catholic.  We wore tube-tops, cut off jean shorts, two piece bathing suits, the modern day attire.
In my late twenties, by the grace of God, I was converted to the traditional Catholic faith.  Actually, the first traditional Mass I attended with my sister I wore blue jeans and a "shop till you drop" sweat shirt.  Bishop Williamson happened to be there that day.  We were both so excited because this was the Mass that we only ever read about in the lives of the saints.
Coming from the world, we had no idea of modest dress.  Of course I saw what people were wearing to Mass and I started to dress in longer skirts for Sunday but did not know there was some standard for everyday.  It took about 10 years before I decided not to wear pants anymore but most Catholic women wear pants during the week.  Those two pictures Ladislaus posted are far more modest than most people wear today.  Of course, in the days of Christendom that would have been totally unacceptable but we have reverted back to paganism and have to pull society back to Christ and His standards.

Well said Michelle!