The crosshairs "arrows" and "shotty" have alternate versions. to swap them all you have to do is:

1) go into the folder with the crosshair that has the folder "alt" in them. example: shotty/alt/
2) open that folder and decide your color, and open the folder with your desired color, every type has 6 color options so choose what you want. for example: shotty/alt/red
3) copy the .png files from those folders
4) go back into the main folder, (example: from shotty/alt/red . go to shotty/ )delete the png that are in the main folder (those are the current equipped ones)
5) after deleting the older ones, paste the new png's you copied from the folder
6) enable the crosshair ingame with the same name