convert parts of a white backround

i have a graph with some curves over a white backround and i like to transform some parts of the backround to an other colour. how can i do this with gimp ???

Re: convert parts of a white backround

Hi Christian If you want to convert all the white background, try the "by Color..." out of the select menu and use the bucket fill afterwards. If you want to select a particular white area which is surrounded by your curves use the magic wand (is this the word in englisch?) ("Zauberstab"),