Color Combination Calculator: How It Works

A color combination calculator takes two or more colors and returns the resulting color when they are mixed, either additively (light) or subtractively (paint, ink). You enter colors as hex codes, RGB values, or HSL values, and the calculator blends them using a chosen mode—most commonly simple averaging or a weighted mix—and outputs the result in the same format you entered. This is useful for designers, painters, and anyone trying to predict what happens when colors are combined.

This calculator mixes two hex colors using the selected mode. For “Average� it simply averages each RGB channel; for “Multiply� it multiplies channel values (normalized 0–1) and for “Screen� it uses the screen formula. The result is shown as a hex code.

Formula

The core formula for additive (light) mixing is:

R_mix = (R₁ + R₂) / 2 (same for G and B)

Where R₁, G₁, B₁ are the red, green, blue values (0–255) of the first color, and R₂, G₂, B₂ are for the second. For subtractive (paint) mixing, the formula is more complex because pigments absorb light; a simple approximation is to multiply the normalized values: R_mix = R₁ × R₂ (with each channel divided by 255 first). The screen mode is R_mix = 1 − (1 − R₁) × (1 − R₂).

Worked Example

Using the defaults: Color 1 = #FF5733 (RGB: 255, 87, 51), Color 2 = #33A2FF (RGB: 51, 162, 255). In “Average� mode:

• Red: (255 + 51) / 2 = 153
• Green: (87 + 162) / 2 = 124.5 → round to 125
• Blue: (51 + 255) / 2 = 153

Result: RGB(153, 125, 153) → hex #997D99. The calculator shows #997D99.

When to Use Each Mixing Mode

Choosing the right mode matters:

• Average – for light (additive) mixing, like overlapping colored spotlights or digital color blending.
• Multiply – for pigment (subtractive) mixing, like watercolors or ink; darkens the result.
• Screen – for light with overlapping projectors; brightens the result.

Real paint mixing is not exactly multiply because pigments have complex absorption spectra, but multiply gives a rough approximation.

Common Mistakes and Limits

A frequent error is mixing hex codes without converting to decimal. Hex #FF is 255, not 15. Another mistake is forgetting that RGB values are 0–255; averaging 255 and 0 gives 127.5, which rounds to 128, but some calculators truncate to 127. Also, mixing complementary colors (like red and cyan) in average mode gives gray, but in paint it often gives a muddy brown—so the mode matters.

The formula assumes linear mixing, but human perception is not linear; the result may look different from what you expect. For more accurate perceptual mixing, you would need to convert to a color space like CIELAB, which is beyond this simple calculator.

How to Choose Colors for Mixing

If you want a pleasing result, start with colors that are near each other on the color wheel. Mixing complementary colors (opposite on the wheel) usually produces a neutral gray or brown. For digital design, use average mode for UI overlays; for print, use multiply to simulate ink.

Frequently Asked Questions

What does a color combination calculator do? It blends two or more colors mathematically and outputs the resulting color, usually in hex or RGB.

Is mixing paint the same as mixing light? No. Paint is subtractive (absorbs light), light is additive (emits light). The calculator’s mode reflects that difference.

Why does my mixed color look different on screen than in print? Screens use RGB (additive), printers use CMYK (subtractive). The calculator works in RGB, so print results will differ.

Can I mix more than two colors? Yes, but the formula extends by averaging all values or applying the mode sequentially. Some calculators support multiple inputs.

What is the difference between hex and RGB? Hex is just a base-16 representation of RGB. #FF5733 = RGB(255, 87, 51).

Does the calculator account for color blindness? No, it only does math. For accessibility, use tools that check contrast ratios.

Related

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in c1 | Color 1 (hex) | #FF5733 | 0
in c2 | Color 2 (hex) | #33A2FF | 0
sel mode | Mix mode | Average=1, Multiply=0.5, Screen=2
out mix | Mixed color (hex) | - | '#' + toHex(round((r1+r2)/2)) + toHex(round((g1+g2)/2)) + toHex(round((b1+b2)/2)) | 0