I bet you enjoy the game a lot, but as soon as you want to keep track of your ammo in your guns suddenly can't see it because your inside or near a cloud or something with the same color as the HUD, well there is a "solution" for that, it isnt perfect but it will do the trick (big thanks to the dev of the game for sharing this solution)

first of all you must search for the game config location, this should be in:
C:\Users\(*your username*)\AppData\LocalLow\Fractal Phase\Sky Rogue\Save\

inside that location look for the file:
GameOptions.sav

you can open that file with notepad (I recommend Notepad++) inside look for the line:
"hudColorHTML":null

replace the null for your hex color of choice (here is a good colorhex website to choose[www.colorhexa.com]) BUT you MUST add a " between the numbers and save the changes.

for example mine is like this:

"hudColorHTML":"007700"

I hope this helps to improve your gaming.

(this is an example with another green I was trying)

thanks to the Dev for this amazing game and his support on this issue.