Ive been looking again and finding a colour is such a hassle! I found a dark one and I tried it and it seemed to match the colour on my cheeks but it was too light for my forehead which is slightly darker! Its trickier than I thought it would be...
Anyway, I think ill have to get my makeup done professionally for the formal, though I still would like some foundation for myself. Maybe ill have to fork out money for an expensive one from myer or something and get them to match the colour for me.
And ill try the bronzer idea!
Thanks for the advice guys!