Just some of the questions asked when this topic comes up:
Morally wrong? No, obviously not! Just as in any other sentence of the pattern "Is it bad to be a _____ who wears makeup?" Whether you put man, woman, stockbroker, housecleaner, opera singer, welder, or catsitter in that gap, it's still not wrong.
Inappropriate in an office situation? Possibly, depending on your workplace and the exact nature of the makeup you like to wear.
Unsafe, because bigots will object violently in public? Possibly. This is also true for cis men who like makeup. And, for that matter, some cis women, because there are bigots who assume anyone with certain kinds of makeup on is a prostitute and therefore subhuman trash to be abused.
Likely to make it harder for you to pass? Depends on your underlying facial structure and a million other things. For this one, start with asking yourself if passing (being reflexively taken for a cisgender man) is particularly important to you. If people, instead of saying "sir" and "he" as a matter of course, eye you sidelong and look confused, or say ".... ma'am?", does that bother you? If so, how much? More or less than the lift and happiness you get from the eyeliner? Just something to consider in your pros/cons analysis.
Does it mean you're not "really" a man? Binary gender-policing is a big snarling bitch. There are even trans women who react angrily towards other trans women who feel most comfortable wearing, say, jeans with a girl-cut t-shirt and a hoodie with no makeup and ballet flats. I have heard "If you weren't going to make an effort, why did you even want to be a woman?" said with a straight face from one trans woman to another. It made me want to punch her, though I know it comes from a place of pain, and a lifetime of habits learned from transitioning back when doctors wouldn't let you transition unless you were girly enough and said all the right things.
Likely to cause pushback from your nearest and dearest about your transition? Possibly. I know there are members of my family that have a real problem with even the concept that "I am a man now" doesn't mean I'm going to give up on wearing sparkly purple when I feel like it, or stop knitting, or think that now I'll magically develop a deep and abiding interest in football, cars, spitting on the floor, and acting like a pig to women. I'm the same person now than I was then, only with fewer self-destructive coping strategies.
But thankfully we live in a more enlightened time, and as long as you keep an eye on your own personal levels of safety and comfort, and whether the makeup is doing more to make you feel good than it is causing people to misgender you and make you feel bad, then by all means -- have fun. Just don't get fired over it, if you can help it.
