Made by Gearbox Software and originally released in 2001 as an add-on to Half-Life, Blue Shift is a return to the Black Mesa Research Facility in which you play as Barney Calhoun, the security guard sidekick who helped Gordon out of so many sticky situations.
Made the crosshair Blue instead of Orange because it was too hard for Gearbox, Lazy Gearbox moment.
Correct me if I'm wrong. Blue Shift never originally had blue crosshairs and only the rest of the hud (health, ammo, basically everything except the crosshair) was the only thing that was in that color? The only gameplay of the WON version I found seemed to have no blue crosshair either.