As I'm getting older my visual scanning speed is going dooowwwwwn. If I look on a shelf with 29 objects looking for the one microphone, it take maybe 1 -2 seconds instead of the maybe half second twenty years ago. So scanning the edge of my project for "Which is the guitar ?" Becomes more of an interruption.
So I made a very simple, TWO LETTER per color block BIG LETTER custom icon sheet in Keynote, Apple's free slide production program. You can screenshot chunks and easily import. Only need to import once to make it available for future.
All the icons are on one slide/page in a Keynote file, and it's all unlocked, you can change colors and labels. Free.
Below is a screen shot, but of course this is just a simple graphic and won't be easy to modify. Feel free to use as is if you don't want to customize.