Mixing two HEX colors comes down to averaging the red, green, and blue channels between them — for each channel you compute round(A × (1 − ratio) + B × ratio), and that weighted average is what every screen-based approach has in common. Comparing approaches to mix two HEX colors mostly means comparing where that math lives, what it does with non-numeric input, and whether it adapts to anything beyond a straight midpoint. Some methods hard-code a 50/50 blend; others expose a slider for the ratio. Some handle extra spaces, missing hash marks, and rgb() strings; others refuse anything but a clean six-digit hex. And some, like physical paint charts, do not match the screen at all. Knowing the differences lets you pick the right tool for the job and avoid results that look muddy or off-brand when they show up in a gradient, a hover state, or a chart palette. The differences are easy to internalize once you see how each method treats the same pair of inputs, and the rest of this guide walks through the three approaches that cover most real design and development work.
The Main Approaches to Mixing Two HEX Colors
Three approaches show up most often when people need to combine two HEX values.
Manual channel arithmetic is the first. You split each HEX into its red, green, and blue integers, compute the weighted average for each channel, clamp the result to 0–255, and convert back to a six-digit hex. Designers used to do this on paper or in a spreadsheet; today it usually happens in a tiny script or a Figma plugin. It is transparent and reproducible, but slow for non-developers and error-prone when you have to re-derive it for every stop in a gradient.
A static midpoint tool is the second. Many online "hex blender" pages only ever give you the exact 50/50 average of two colors. That covers a small share of real use cases — finding a middle tone between two brand colors, say — and ignores the long tail where you want 30% of one color mixed into 70% of another to bridge a palette or soften a hover state.
A ratio-driven mixer is the third, and the most flexible. You type or pick two colors, drag a slider that goes from 0% to 100%, and read the blended hex plus the rgb() string instantly. A good one also renders a gradient bar so you can preview every step at once. The Color Mixer is built around this approach, and the rest of this guide leans on it for the worked steps.
Why sRGB Linear Interpolation Is the Default
Screen-based tools do not all use the same math. Some blend in linear light, some in gamma-corrected optical space, and some in HSL or LCH. For most on-screen work — websites, apps, icons, dashboards, slide decks — sRGB linear interpolation is the safe default because it is the same math CSS gradients, design tool color pickers, and the vast majority of UI frameworks already use.
The formula is the one quoted in the opening: for each of the red, green, and blue channels, result = round(A × (1 − ratio) + B × ratio). At a ratio of 0 you get pure A. At 1 you get pure B. At 0.5 you get the exact midpoint of the two channel values, with channels clamped to 0–255 and rounded. It is a direct weighted average of 8-bit sRGB values — additive-style screen-light blending, not gamma-corrected light mixing and not subtractive pigment mixing.
That distinction matters because mixing pure red (#ff0000) with pure blue (#0000ff) here gives clean magenta (#800080), while physically blending red and blue paint on a palette gives a muddy dark purple or brown. If you are matching digital colors for any on-screen deliverable, sRGB linear interpolation is what you want. If you are predicting how acrylics or printer inks will behave on paper, no screen-based blend will model that accurately.
How to Blend Two HEX Colors With the Color Mixer
Use the Color Mixer when you want exact, reproducible blends at any ratio without doing channel math yourself.
- Type your first color into the Color A field. A short hex like #f00, a full hex like #3b82f6, or an rgb() string like rgb(59, 130, 246) all work; the parser tolerates extra spaces, missing hash marks, and upper- or lower-case letters. You can also click the swatch next to the field to pick a color visually.
- Enter your second color in the Color B field the same way.
- Drag the ratio slider to set how much of each color goes into the blend. Zero percent is pure A, 100 percent is pure B, and 50 percent is the exact midpoint of the two channel values.
- Read the result panel for the blended hex (lowercase six digits) and the matching rgb() string. The gradient bar above the result shows eleven evenly spaced blend steps between your two colors so you can eyeball where a pleasing intermediate lives.
- Click Copy to put the result hex on your clipboard, then paste it into CSS, a design file, or a chart palette.
Because the slider updates the result instantly, you can sweep from 0% to 100% in a single motion and watch the gradient change in real time. The ratio label always reads the current split — for example, 70% A / 30% B — so the outcome is reproducible later.
Comparing the Approaches Side by Side
The table below lines up the three approaches on the dimensions that usually decide which one to reach for.
| Dimension | Manual channel math | Static 50/50 tool | Ratio-driven mixer |
|---|---|---|---|
| Output ratio | Any ratio you compute | Fixed at 50/50 | Any ratio via slider |
| Input formats accepted | Whatever your script parses | Usually full hex only | Short hex, full hex, rgb() |
| Gradient preview | Manual | None | Built-in gradient bar |
| Reproducibility | High if you save the formula | Always the same result | Slider position locks the result |
| Best for | Programmatic blends, batch scripts | Quick midpoint checks | Designers picking a stop in real time |
| Server requirement | Runs anywhere code runs | Varies by tool | Runs in the browser, no upload |
A few cells are worth flagging. "Static 50/50 tool" looks weak in this comparison, but it is genuinely the right pick when all you need is the geometric middle of two specific colors and nothing else. "Manual channel math" looks strongest on flexibility, but it loses to a ratio-driven mixer the moment you need to iterate visually rather than numerically. None of the three rows address pigment mixing; that is a separate problem and not something any of these approaches claim to solve.
When to Pick Each Approach
Manual arithmetic still wins when the blend is part of a larger pipeline — generating fifty gradient stops for a chart, seeding a color scale from two endpoints, or reproducing the same blend deterministically across builds. Anything that lives in code belongs here.
A static midpoint tool is enough when the question is genuinely binary: what does the middle of these two colors look like? Designers picking a single bridging tone for a brand refresh, or a developer sanity-checking that two CSS variables land where they expect, do not need a slider.
A ratio-driven mixer is the right pick whenever you need to compare the look of the blend at several ratios before committing. Building a hover state that sits 20% toward a secondary brand color, finding a tint halfway across a palette, sampling steps for a chart — these are slider problems. The Color Mixer in particular also gives you a gradient bar with eleven evenly spaced steps, so the eye-balling step is faster than typing ratios into a calculator.
A quick rule of thumb: if you already know the exact ratio you want, use code or a 50/50 tool; if you are still choosing the ratio, use a slider.
Worked Example: A 60/40 Brand Bridge
Imagine the brand color is #2563eb (a deep blue) and you want a slightly warmer companion at #ef4444 (a clean red), blended 60/40 in favor of the blue. With the formula result = round(A × (1 − ratio) + B × ratio) and ratio = 0.4:
Red channel: round(0x25 × 0.6 + 0xef × 0.4) = round(37 × 0.6 + 239 × 0.4) = round(22.2 + 95.6) = round(117.8) = 118 = 0x76
Green channel: round(0x63 × 0.6 + 0x44 × 0.4) = round(99 × 0.6 + 68 × 0.4) = round(59.4 + 27.2) = round(86.6) = 87 = 0x57
Blue channel: round(0xeb × 0.6 + 0x44 × 0.4) = round(235 × 0.6 + 68 × 0.4) = round(141 + 27.2) = round(168.2) = 168 = 0xa8
That gives #7657a8, a dusty violet. Drop those three channel values into the Color Mixer with the same inputs and the slider at 40% — the result panel should match. If it does, you have a reproducible answer you can paste straight into a CSS file, and the gradient bar will show you what the 30% and 50% stops look like for free.
Things That Change the Outcome
Two inputs that look identical to a designer can still produce slightly different blended colors depending on how the tool handles them. Worth keeping in mind:
- Short hex versus full hex — both should parse to the same three channels. If a tool treats #f00 and #ff0000 as different inputs, switch tools.
- Uppercase versus lowercase — RGB has no case, but some hex parsers reject anything other than lowercase. A good tool accepts both.
- Spaces inside rgb() — rgb(59,130,246) and rgb(59, 130, 246) are identical values; a forgiving parser treats them as such.
- Missing hash mark — ff0000 should still parse as red. Anything that rejects it is being strict for no good reason.
The Color Mixer tolerates all of these so you can paste in whatever shape the source gave you. Everything runs locally in your browser, so nothing is uploaded and there is no sign-up or usage cap — useful when you are cycling through dozens of blend candidates while a design is still in flux.