To customize the HUD color go to "Config/View", open view.lua with notepad++ and modify these lines:
-- HUD RGB color
HUDColor = {}
HUDColor[PlaneIndex.iSu_27] = {[color=red]0, 255, 0[/color]}
HUDColor[PlaneIndex.iSu_33] = {[color=red]0, 255, 0[/color]}
HUDColor[PlaneIndex.iSu_25] = {255, 255, 0}
HUDColor[PlaneIndex.iSu_39] = {[color=red]0, 255, 0[/color]}
HUDColor[PlaneIndex.iMiG_29] = {[color=red]0, 255, 0[/color]}
HUDColor[PlaneIndex.iMiG_29K] = {[color=red]0, 255, 0[/color]}
HUDColor[PlaneIndex.iA_10] = {[color=red]0, 255, 0[/color]}
HUDColor[PlaneIndex.iF_15] = {[color=red]0, 255, 0[/color]}
HUDColor[PlaneIndex.iKA_50] = {[color=red]0, 255, 0[/color]}
Can't tell for transparency tough
Voilà!