Color palette for blue

Key takeaways

• Blue is #0000FF, rgb(0, 0, 255), hsl(240, 100%, 50%), CIELAB 32.3, 79.2, -107.9.
• Contrast: 8.6:1 on white and 2.4:1 on black. White text on blue passes the WCAG AA minimum of 4.5:1.
• Its complement is #FFFF00; the analogous colors are #0080FF and #8000FF; the triad is #0000FF, #FF0000, #00FF00.
• 3 of the 9 tints and 9 of the 9 shades have at least 4.5:1 on a white background; the first shade that does is #0000E6.
• Photographs rich in blue gave #5688BF, #7C93CB, #7E9EEF, #5B75D4, #A0BEF2, #30478C; the nearest of their colors to #0000FF was 20.5 CIEDE2000 units away.
• For people with deuteranopia the closest pair in the triad is 19.4 apart, against 52.9 for typical vision.

Measured: a palette for blue, from photographs

On white it has a contrast ratio of 8.6:1 (passes the WCAG AA minimum of 4.5:1 for normal text) and on black 2.4:1. A palette extracted from three photographs rich in blue (91%, 84% and 73% of their pixels near the hue) came out as #5688BF, #7C93CB, #7E9EEF, #5B75D4, #A0BEF2, #30478C.

We searched Wikimedia Commons for blue subjects and kept photographs under Creative Commons or public domain licenses. Of 30 candidates we kept the three with the largest share of pixels within 30 degrees of the hue of the color, with saturation of at least 30% and lightness between 20% and 85%. The tool's own palette code (k-means in CIELAB, no random numbers) found five colors in each photograph. The six colors in the table below come from only the pixels inside the color window, from the three photographs, so they are six shades and neighbors of blue rather than the whole picture.

Blue appears here as near steelblue, near cornflowerblue, near cornflowerblue, near royalblue, near lightsteelblue, near darkslateblue. The photo palette is a starting point: colors from a photograph are rarely pure, and the table shows how each performs as text on white and black.

Measured: the photographs

The photographs are credited with their Wikimedia Commons license. The extracted lists are the exact tool output.

Colors that go with blue

The complement, #FFFF00, sits opposite #0000FF on the color wheel (hue + 180 degrees); Wikipedia's color scheme article describes analogous schemes as neighbors on the wheel and a triadic scheme as colors 120 and 240 degrees apart. Under protanopia, deuteranopia and tritanopia the colors are simulated with the Machado model at full severity; a closest pair below about 10 is hard to tell apart.

Blue in numbers

Tints, shades and accessible text

3 tints and 9 shades reach 4.5:1 against white. The WCAG success criterion 1.4.3 asks for at least 4.5:1 for normal text and 3:1 for large text; criterion 1.4.6 asks for 7:1 for the enhanced level.

Use it in CSS

:root { --blue-1: #5688bf; --blue-2: #7c93cb; --blue-3: #7e9eef; --blue-4: #5b75d4; --blue-5: #a0bef2; --blue-6: #30478c; }

The complement and analogous colors of #0000FF: #FFFF00, #0080FF, #8000FF.

Free tools:Color palette generatorPalette from an imageImage to textCompress an image

Check the contrast before you use it for text

• Blue #0000FF on white: 8.59:1; on black: 2.44:1.
• The darkest shade in the table, #00001A, reaches 20.69:1 on white.
• Large text (at least 18 point, or 14 point bold) needs 3:1; normal text needs 4.5:1; the enhanced level needs 7:1.
• Do not use color as the only way to tell things apart: about 1 in 12 men have a color vision deficiency.

How the numbers were made

The hex value of blue is the W3C CSS named color. Harmonies rotate the hue in HSL and keep saturation and lightness. Contrast follows the WCAG 2 definition with relative luminance. Color differences use CIEDE2000, which Wikipedia notes is designed so that a difference of 1.0 stands for a just noticeable difference. Color blindness is simulated with the matrices of Machado, Oliveira and Fernandes (2009) at severity 1.0. Palette extraction: pixels are grouped into 32 levels per channel and clustered with k-means in CIELAB; the same picture always gives the same palette. The accuracy test on pictures of known colors is on the palette generator page.

Questions people ask

Related

Sources and how we checked

1. W3C: CSS Color Module Level 4 (named colors) (read 2026-10-10)
2. W3C: Understanding Success Criterion 1.4.3, Contrast (Minimum) (read 2026-10-10)
3. W3C: Understanding Success Criterion 1.4.6, Contrast (Enhanced) (read 2026-10-10)
4. Wikipedia: Color scheme (read 2026-10-10)
5. Wikipedia: Color difference (CIEDE2000) (read 2026-10-10)
6. Machado, Oliveira and Fernandes: A physiologically-based model for simulation of color vision deficiency (2009) (read 2026-10-10)
7. Wikimedia Commons (the photographs, under the licenses shown) (read 2026-10-10)

Reviewed October 10, 2026. The palettes were found with the tool's own code from Creative Commons photographs; contrast, harmonies and color differences are computed. The files and results are in data/seo/hub/evidence/2026-10-10/palette.