i think silver black or gunmetal would be the colors you would shoot for... thats just my personal preference... red and yellow instantly screams mcdonalds to me... i think yellow and blue are so wayy off... yellow accents is nice though...
as long as the part you paint arent the block or anything directly dealing with tremendous heat you should be alright... if your thinking of painting ur engine cover that would hold up well... i shot mine with spray paint and it lasted a year with no problems... i color matched it though to SR my color of my z....