I've witnessed this:
(concerned) Is x OK?
Huh?
Is she upset? She looks like she's been crying.
(realising) No, she's just not wearing any makeup. You normally see her with makeup on.but you can talk to men how you want, they won't care.
so yes you have to behave differently to both genders.
However, the reasoning for that is interesting - the primary reasons women get more upset when you speak about their appearance negatively when compared to men is that women constantly have it drilled into them that their appearance is one of the most important things about them, from a relatively early age. We have a combination of media and other people who do that - often even other women.
It's something to be solved, but as the situation stands right now, yeah, criticising women on their dress/makeup/haircut only serves to further that - because women have generally already had significantly different experiences than men by the time you meet them.