erm??

colour to a picture??

u mean a model?

Select the object, right click it and hold. Click on assign new material > then in the attributes editor, click Lambert or type of material you choose, then change th colour.


Or you can manually change the colours on parts of an object, by selecting verts.

If its a polygon obect, go to Edit Polygons > Colours > Apply Colour and tick box to change the colour.

Hope this helps. Sorry if im way off from what you meant, im assuming this is what you mean.