right ive got the slomo part sorted, the console command is host_timescale and you can trigger it in-game through a point_clientcommand and YAY! Slomo! But im still trying to work on the colour thingy, does anyone know how valve triggered it for the start sequence, that could help me understand it a bit more.
EDIT: i know now you can do black and white with mat_yuv i think it is, but writing my own colour thingy like valve did fir the intro is my main concern now so if anyone knows - please help