Gam,
“Okay, going with your example. What is wrong with wearing skin colored clothing? I can think of two issues- 1) it’s provocative 2) maras ayin.”
Another difference is skin is a definite Ervah and provocative, which is why its applicable even to girls. Hair is not exactly that only when intact. If hair would be that much provocative girls would be considered an Ervah for girls as well.
Note: some poskim are even mattir to say Kriyas Shma in presence of uncovered hair where going with uncovered hair is the norm – but never any other body parts… (see Aruch hashulchan Ch 71, Shvilel L’David Ch 3)
על כרחך – שיער [נאסר] מטעם כמוס, שליטת הקליפה, ואינו תימהון דוקא במחובר. וכמו בשיער אשה מונח לפניו, אינו כלום .וכמה דברים שלא נגלו טעמם
– מאורי אור חלק קן טהור, דף קצ״ד ע״א-