The following color filters group contains miscellaneous filters to modify colors in an image, a layer or a selection. You can find some nice effects here.
Section 11.32, “ Colorify ”
Section 11.33, “ Color to Alpha ”
Section 11.34, “ Filter Pack ”
Section 11.35, “ Hot ”
Section 11.36, “ Max RGB ”
Section 11.37, “ Retinex ”