Steam/SteamApps/Common/Left 4 Dead/left4dead/cfg/autoexec.cfg
if there is no autoexec just make one just make a new txt file and change after saving the .txt to .cfg presto!
//Crosshair
cl_colorblind "0" (Maybe for Waz set on 1)
cl_crosshair_alpha "225" (default 255)
cl_crosshair_red "66" (default 138)
cl_crosshair_green "219" (default 182)
cl_crosshair_blue "49" (default 220)
cl_crosshair_thickness "1" (default 2)
cl_crosshair_dynamic "0" (accuracy/recoil autosizing - default 1)
cl_crosshair 1
//NewbiesIncBlueGlow
cl_glow_item_r 0.5
cl_glow_item_b 1.0
cl_glow_item_g 0.5
cl_glow_item_far_r 0.0
cl_glow_item_far_b 1.0
cl_glow_item_far_g 0.5
//Detail
mat_grain_scale_override "0.000000"
mat_monitorgamma_tv_enabled "1"
Enjoy!