Hi, what you need is a green tinted concealer. The green colour counteracts the redness. You can get such products from MAC and most other beauty counters at your local department stores!
I've found "Fade Out" quite effective, its another green concealer
TIP: make sure its all rubbed in or you'll get a comment of "did a bird c**p on you? There's some green stuff on your face".... not the most dignified moment of my life..