by Julieanne Kost
The sixth group of Blend modes have no neutral colors. They work in a hue, saturation, luminance space that is similar to but different from both HSB and HSL. In particular, while hue is the same in all three spaces, all of the spaces define saturation and brightness/lightness/luminance somewhat differently. All of the combinations described below are subject to clipping to keep the values in the valid RGB range.
• Hue – Creates a result color with the luminance and saturation of the base color and the hue of the blend color.
• Saturation – Creates a result color with the luminance and hue of the base color and the saturation of the blend color. Painting with this mode in an area that has no (0) saturation (gray) causes no change.
• Color – Creates a result color with the luminance of the base color and the hue and saturation of the blend color. This preserves the gray levels in the image and is useful for coloring monochrome images and for tinting color images. Color yields a result with the same hue and saturation as the upper color and the luminance of the lower color.
• Luminosity – Creates a result color with the hue and saturation of the base color and the luminance of the blend color. This mode is the inverse of Color mode.
One of the common uses of the Color blend mode is for selective coloring effects using the painting tools, gradient fill layers and layer effects. For example, you can select the paint brush, set its blend mode to color and paint directly on an image (but this isn’t very flexible if you make a mistake). For more flexibility, you can choose to create a new layer and set it’s blend mode to Color and set the paint brush’s blend mode to Normal to paint any part of an image.