Highlight

This option simulates a highlighter pen. Combine this with a custom brush to create realistic and artistic hightlights.

Recolor

This option replaces colors in the image with color 1, without affecting the natural tone and lighting of objects in the image. In the example below, all colors are being replaced with purple.

Selective Recolor

This option replaces colors in the image with color 1, but only where the hue closely matches color 2, without affecting the natural tone and lighting of objects in the image. The effect level determines how selective it will be. In the example below, the only colors being replaced with purple are the red hues.

Chroma Blur

This option spreads out color without affecting texture or sharpness.

Colorize Foto

This option is used to add color to black-and-white photographs. The brush adds color 1 to the area while maintaining brightness and tone. Just run it over the area to be colored. See the coloring tutorial for more information.

Colorize Toon

This option is used to add color to black-and-white drawings and cartoons. The brush adds color 1 to the area while maintaining brightness and tone. Just run it over the area to be colored. See the coloring tutorial for more information.

Decolorize

This option is used to remove color from photographs.

Sepia-tone

This option is used to add a sepia-tone effect to photographs.

Underpaint

This option is used to apply background color to transparent/translucent areas in a layer as if one was painting behind it. Just run it over the area to be underpainted.

Overpaint

This option is used to apply foreground color to opaque areas in a layer as if one was painting on the object in it. Just run it over the area to be overpainted.

Dodge

This option is used to brighten under-exposed regions of a photograph.

Burn

This option is used to darken over-exposed regions of a photograph.

Red-eye Reduction

This option attempts to correct the red-eye effect introduced by the "flash" used by digital cameras. Just run it over the red portion of the eye.

Shadow

This option is intended for applying regular shade, for example a shadow.

Smoke

Acts like a translucent brush of some sort - it adds just a little bit of the selected color to the area. You can use it to draw smoke by adding a little black to the area over a chimney, for example. Or some white to the sky for clouds...

Pixelate

This option is used to apply censorship to images where privacy or ethical issues are a concern. Just run it over the area to be censored.