https://elite-dangerous.fandom.com/wiki/HUD_Color_Editor

There is another way on Windows with much more options but AFAIK no one has managed to run it on Linux. It relies on injecting a dll into ED

You can do it per ship too, makes every ship feel unique. Highly recommended. Edhm ui

I know this is an old thread but I just wanted to say, for anyone who might find it, that you don't necessarily need a plugin, you can change your colors on any platform by just changing a text file, "GraphicsConfiguration.xml". Where it is located depends on where you installed the game, but as an example, if you installed it through Steam, it will be at /path/to/your/install/SteamLibrary/steamapps/common/Elite Dangerous/Products/elite-dangerous-odyssey-64.

Make a backup copy of it, then edit it. Search for "GUIColour" and find this block:

<Default>
	<LocalisationName>Standard</LocalisationName>
	<MatrixRed>1, 0, 0</MatrixRed>
	<MatrixGreen>0, 1, 0</MatrixGreen>
	<MatrixBlue>0, 0, 1</MatrixBlue>
</Default>

You can change this to any number of different color variations. The one I use is this:

<Default>
	<LocalisationName>Standard</LocalisationName>
	<MatrixRed>0.5, 0.5, 1</MatrixRed>
	<MatrixGreen>0, 0.5, 0</MatrixGreen>
	<MatrixBlue>1, 0, 0</MatrixBlue>
</Default>

And it makes it look like this.

Edit: The plugins give greater control over more elements, but if you just want a quick and easy way to do it, this works pretty well.