[juliansader]

I wondered about the same thing in the old thread MIDI Color Map Explanation, and Commala answered:

Originally Posted by Commala

I was just having a look into this:

When you create a midi item with no assigned colour, they will be automatically assigned a colour from the channel section of the midi note colour map. You can see this by looking at that item's colour swatch in the midi editor tracklist.

So what is happening is that when the midi editor is set to colour notes by track, the outlines of selected notes are using this randomly assigned colour. What's weird is that if you explicitly colour an item, you'll see that reflected in the tracklist, but the note outline colour will remain the randomly assigned colour.

If the track has not been coloured, the entire note will appear this random channel colour, not just the outline.



On a somewhat related note:

I'd love to see the whole 'colour by track' option get an overhaul. It's graphically very inconsistent, but it makes sense why. If you think about it, Reaper depends on the midi note colour map to render the notes. There is (currently) no mechanism to take an external rgb value and render notes to appear as if the map contained another column based on that colour. Remember, each column in the map could be composed of any number of separate colours, gradients, etc. How/where do you apply an external rgb value to an existing column to get a visually consistent output?

Possibly, a "key" column could be added to the map specifically for this function. It would likely give most predictable results if the themer made that column a desaturated and value balanced replica of the other columns in the map. Then, Reaper could colourize that column according to the custom colour input, and thereby achieve (greater) consistency across all note-colour modes. Although I find that hue-shifting gives better results than colourization, that might be much more complicated to implement than this already sounds.

I agree with Commala that "colour by track" needs an overhaul.