Professional Work Nail Polish Colors

[#1]

As part of my Foundations of Education class, I have to do a minimum of 12 hours of classroom observations.  Although students are allowed to wear nice jeans, most teachers will mark down on evalutations for those who wear nice jeans.  So, I'm not going to risk that, and I'm going to go all out.  It might help in the future.  Anyway, I always have my nails polished.  I know not to wear my neons, glitters, etc, but I'd like some tips on colors and designs.  For example, would it be ok to wear a french white tip with a colored stripe below it?  Any advice is greatly appreciated.

[#2]

I work at a bank and experience the same issue. I love nail polish, but feel that I'm limited in the colours I can use so I don't look "unprofessional". Usually I paint my nails black, dark purple, red, pale pink, or have a french manicure. Now that summer is here I'm trying to incorporate more summery colours into my "work nail polish" by using pastels. I find that because the pastels are softer I can get away with using colours without it looking inappropriate at work. 

Hopefully this helps!