together

I dunno why I named this piece with a crappy title..its not even romantic..just a couple having picninc on a rainbow...BTW,I failed to colour the rainbow by using the 7 colour so I changed it to an easier way...*shoot head*...but I like colouring the hair and the cake.I was trying to make the pic look soft but failed and made the colour too dull... ..Anybody know how to change the line colours..I've yet too see any lineart tutorial explaining how the lines could be coloured..>.>