You can adjust almost any color in the game to a color better suited to your eyes by opening the Sins of a Solar Empire/Window/Colors.color file which can be edited with notepad like most Sins data files (for ease of modding). The names of the colors should all be self explanatory but the color format might not be.

Let's look at an example:

attackRangeColor 40ff5b00

This is a red color of the gun enplacement range rings in hexidecimal format. Simply copy and paste the last 6 digits into Photoshop or any other modern paint tool to see what the actual color looks like. You can then replace those last 6 digits with a color you can see better. If I wanted it to be all white i would change the value to 40ffffff.

The the first 2 digits (in this case 40) refer to the transparency or alpha value. ff would mean fulling opaque and 00 would mean fully transparent.