I happen to be of the opinion that all femme women are beautiful ---femmes are amazing - beautiful - intriquing- sexy - captivating women -which is why we butches love them - right? - So it is for us to compliment them before they should need to ask - unless they are asking in that playful teasing way - that only they know how to ask?
However like others have posted I don't just think it is across the board not just femmes - we seem to have a hard time accepting compliments sometimes or off put someone who does - a simple smile or thank you is all that is needed - to rebuff someones genuine compliment is to take away their (blessing) so to speak.
We all need to compliment each other more - butches and femmes alike - and not just about clothing - but the way perhaps she smiles or how her eyes twinkle when she sees you or the shy way she slowly takes your hand - or perhaps how boldly and passionately she kisses you in public - just because - or the way she tosses her head back and laughs - that is just so amazing - lots of ways to compliment ---my advice --take notice of them all!