Triadic Colors Calculator

How it is calculated

The tool reads a hex colour (3 or 6 digits, with or without #; 3-digit shorthand such as f80 is expanded to ff8800) and converts it from RGB to HSL: hue H in degrees, saturation S and lightness L. It keeps S and L fixed and rotates the hue: H + 120° and H + 240° (the same as −120°). Each result is converted back to RGB and rounded to whole 0-255 channel values, so a partner can differ from a theoretical value by one unit per channel. The output lists the base colour and both partners as uppercase hex codes. Anything that is not 3 or 6 hex digits, such as an 8-digit code with alpha or rgb(...), returns nothing.

Common mistakes

• Entering an 8-digit hex with an alpha channel, such as #1E6BFFCC, or a colour written as rgb(30,107,255). The tool accepts only 3 or 6 hex digits, so remove the alpha or convert first.
• Expecting the partners to have the same perceived brightness. Equal HSL lightness does not mean equal visual brightness, so a yellow-green partner can look much lighter than a blue base.
• Entering a grey, white or black. They have no saturation and so no hue; all three codes come out identical (for example #808080 three times), because there is nothing to rotate.
• Using all three colours at full strength in the same area. Triadic palettes work best when one colour dominates and the others are accents.
• Expecting a 60° or 90° split. The tool always rotates by exactly 120° and 240°; for other schemes, a different tool is needed.