Tetradic color schemes use four colors arranged as two complementary pairs. They are the richest of the classic harmonies — offering the most variety while still following a structured rule. They are also the hardest to balance.
What Is Tetradic?
A tetradic palette uses four colors that form two complementary pairs. The most common arrangement is rectangular: colors at H, H+90°, H+180° and H+270°. Square tetradic uses colors exactly 90° apart.
Examples of rectangular tetradic:
- Base at 0° (red) → 90° (yellow-green), 180° (cyan), 270° (purple)
- Base at 215° (blue) → 305° (magenta), 35° (orange), 125° (green)
Why Tetradic Is Rich but Difficult
With four colors, you have maximum flexibility — but also maximum opportunity for chaos. Every color competes with the other three. Without hierarchy, tetradic palettes look like a paint spill.
How to Balance Tetradic
60-30-10 with Extension
Adapt the classic rule:
- 60% dominant — neutral background or one color
- 25% secondary — one complementary pair
- 10% accent — the other pair, used sparingly
- 5% pop — the fourth color for tiny highlights
Use Neutrals Heavily
Tetradic palettes need white, black, gray or beige to hold the four colors together. Without neutrals, the palette is overwhelming.
Pair Related Tones
Instead of four fully saturated colors, use slightly different lightness values for each to create visual hierarchy.
When to Use Tetradic
- Complex dashboards — Four distinguishable series colors
- Multi-page websites — Different sections with distinct color identity
- Illustrations — Multi-hue compositions with structure
- Gaming interfaces — Factions, classes, teams
- Event branding — Multi-track conferences, festivals
When NOT to Use Tetradic
- Minimalist interfaces — Too many colors
- Luxury brands — Too varied
- Landing pages — Too busy for focused conversion
- Clinical or formal brands — Feels playful
Tetradic vs Square
Square tetradic uses four colors exactly 90° apart (like at 0°, 90°, 180°, 270°). Rectangular tetradic uses the same count but places the two pairs at unequal distances. OmniColor generates rectangular by default.
Accessibility
Tetradic palettes are the most likely to fail WCAG because four vivid colors rarely have good contrast against each other. Always verify text on backgrounds with our contrast checker.