California recently established a new policy requiring that all women wear a jacket or sweater when entering the assembly chamber. NCSL's The Thicket blog has the story here. This applies to visitors, media, and legislative aides.
It appears that with the weather so hot this summer, bare sleeves and shoulders became more prevalent. Female lawmakers already abide by the requirement to wear appropriate business attire while in the chamber, with an unwritten agreement to avoid sleeveless tops and dresses. The definition of business attire seems fairly flexible, though.
This is my understanding of the dress code in the Hawaii State Legislature. Men and women are required to wear business attire on the floor, and that specifically means a suit or jacket. The exception is on Fridays when aloha attire is permitted.