This is a great online color tester and designer. Unlike other hex code color testers, this application can also test hex colors on a selected background and guides you in color mixing. Type the color(s) in 3 or 6 digit hex code format eg. #A9BBE7, #ABE or RGB numbers format eg. 169, 187, 231. Backgroud color is optional. Default value FFFFFF (white) is selected when no value supplied for bg color. (Note: no matter whether the symbol # is used in hex code or not.) The online color tester also helps you to select the harmonic color combinations. The complementary, triadic, analogous, split complementary, tetradic and square color schemes in the Color combining guide recommend you the best color groups for the two, three or four color design. You can also pick up the colors from the gradient scale, best brightness (lightness) level from tints or shades scale and the best suitable vibrance level from the saturation scale. Moreover you can pick the color you like from the random color palette generator. Color tester also shows you the negative and monochrome (grayscale) representation of selected color and the closest websafe color. You also find there the RGB and CMYK representations calculation.