Why would you need to tell a female coworker that she is "looking good?" What does this phrase have to do with job performance?
Ive been working since Ive been roughly 14-15 years old, and I have never had the urge to tell a female co worker that she is "looking good." And this was way prior to all the of the sexual assault allegations.
In all of my years of working, some female co-workers will say things like, "Nice/cute haircut" or "nice shirt." However, if I have not received these compliments, it would in no way affect my job performance.
Really, I see no need to offer anyone compliments at work unless it pertains to their job performance.