Sorry if this has been done before, I tried doing a search but the search engine doesn't distinguish between 'dyeing' and 'dying' 
Anyway, I'm expecting DC2 in a few months and while I don't need to buy many new clothes, DD's old cotton sleepsuits and vests were white but are now a bit grey and could use brightening up a bit.
Is it safe to dye baby clothes and if so, what dye should I use? I've never dyed any clothes before so something simple would be preferable although I'm open to new ideas.
I'd like to go for bright colours like green and yellow, absolutely no pastels or baby pink/blue! 
TIA :)