Zuperman, I set custom crosshairs to yellow, now the enemy shows as yellow instead of red. 
Latest update, win 10.

Also a big THANK YOU for all your efforts and changes, especially stopping the spawn crashes!

UPDATE:  I changed color as zup suggested in game, to green.  Enemies were then green, crosshairs stayed yellow.  I then changed to red, enemies red, cross hairs still yellow.  All good.

Hey pappy there is the enemy box target color and cross hair color go to setting and to  Graphics you find which one you changed 

I've tried myself to reproduce this with no luck.

Wow, Senior  moment/  Did not see the separate color selectors for cross hairs and target colors.  That explains a lot!