Thank you!!
So, the problem I have with making the outline colors too flat is that it won't stand out against different backgrounds. (If our monkey boy is, for example, a solid dark gray, he will blend in with a dark background; and vice versa if he's light.) We could get around that by surrounding him with a colored shape, like for example the Discord logo. At the risk of looking like we're copying VLC and Google Play Music, I came up with this li'l guy:
Edit: Added a blue version, too, if interested!

It's kind of a drastic change, and it's a bit of a risk to look "generic", but... it's kind of grown on me? And it does kinda look like it would fit as an Android app logo.
Back on Earth, however, here are some modifications to the first icon suggestion; I made the monkey brighter and the circle darker, and also made one with no outline and one with an orange outline.

Personally... I'm not the biggest fan of any of these; The first and third don't really feel right, and although the one in the middle looks pretty good, it kinda looks like it's a shadow of a monkey dancing in front of the sun. Gives me "tropical" vibes, as if it's the logo of a beer company.
Somehow, I keep getting drawn back to the first two.

What do you think? Maybe I could try making much more subtle brightness changes to the monkey/circle, to make it not as jarring but still help them differentiate a little better?
Thanks again for listening to my input, it really means a lot that you'd consider my ideas. MediaMonkey is by far my favorite music library program, and it makes me really happy to take a part in it.
