I sometimes have score notation in Cantabile live notes, and it works great except typically score software generates white on black scores, which can be rather bright and glaring on a dark stage. So I’ve discovered using PNG files with a transparent background, allowing me to choose a background via Cantabile’s show note interface (without needing to pass the score through an image editor to modify colours). This allows me to tone down the score colours as well as have the colour state-driven, which is nice. But the selection of colours for show notes is quite limiting, and on the dark or too colourful side for this. Cyan is about the only colour that really works well.
So I was thinking, wouldn’t it be nice if the 15 colours we get for show notes, rack/plugin colours, and on-screen keyboard route ranges could be edited? Partly also because there are some colours I don’t think I’d ever use, and I bet I’m not alone in this (olive reminds me a bit too much of early parenthood and fun with nappies/diapers 
). It would be nice to tailor the available colours to our own preferences and uses. For example, I bet some people only use them for route ranges, in which case maybe bright colours are best. And other people might only use them for show notes background, where they might want some more subtle shades.
I’ve discovered that these can be edited manually in the theme.json file within themes, but it’s cumbersome, and adds the burden of needing to update and maintain local theme files when the shippped themes are extended, which isn’t ideal.
Just a thought 
Neil