I find if you look at the word boxes ( i.e. red, yellow etc etc) at the bottom and dont look at the actual coloured word as it comes up on the screen then you see the colour first, the hardest thing for me is the green and yellow which look similar on my monitor so i have to actually look at the word...and get it wrong!!
or when they start coming up pretty fast then i cant move my mouse pointer fast enough on account of being old and feeble!!
aaah my missus studied something similar to this she had a fecking huge piece of coursework to do on it. so i was guinea pig for loads of these test. the trick is to not read the word just look at a letter and get the colour from that.