i too was recently looking for food colouring. i could only find yellow liquid in the supermarkets and powdered stuff in dark brown bottles. i tried the orange and its a frightful colour!!!
my friend has put me onto the 'wilton' brand of cake decorating equiptment etc. u can get HEAPS of colours in a small bottle that is a gel. u buy it from tavola in royal plaza in al saad street/road/whatever it is!! QR11/bottle and will last u a lifetime of decorating. ask the girls in the shop how to use it ... i found them very helpful. they sell fondant by the kg too