#21579A
Closest named color: Dusk Blue (#26538D). oklch(45.8% 0.123 255.7), rgb(33, 87, 154).
Aa
White text reads best on this color (7.25:1).
About this color
#21579A is a medium-dark, moderately saturated blue. In OKLCH its lightness is 46%, its chroma 0.123 and its hue 256°. Its hue sits on the cool side of the wheel. The nearest named color is Dusk Blue (#26538D), ΔE 0.022 away. White text reads best on it, at 7.25:1.
| Hue family | Blues |
| Lightness | medium-dark (46%) |
| Chroma | moderately saturated (0.123) |
| Temperature | cool |
| Nearest name | Dusk Blue (#26538D) |
| Black text | 2.89:1 |
| White text | 7.25:1 |
Values
| HEX | #21579A |
| RGB | rgb(33, 87, 154) |
| HSL | hsl(213, 65%, 37%) |
| OKLCH | oklch(45.8% 0.123 255.7) |
Contrast
WCAG 2 contrast ratios are the conformance target: AA needs 4.5:1 for body text and 3:1 for large text, AAA needs 7:1. APCA Lc values are supplementary guidance from the WCAG 3 drafts.
| Pair | WCAG 2 | Result | APCA | APCA guidance |
|---|---|---|---|---|
| White text on #21579A | 7.25:1 | AAA | Lc -89.7 | Fine for body text |
| Black text on #21579A | 2.89:1 | Fails | Lc 19.2 | Dividers and decoration only |
| #21579A text on white | 7.25:1 | AAA | Lc 84.8 | Fine for body text |
| #21579A text on black | 2.89:1 | Fails | Lc -17.2 | Dividers and decoration only |
Tints and shades
A 50–950 scale built in OKLCH: the hue is held, lightness follows a Tailwind v4-like curve, and every step is kept inside the sRGB gamut. This color sits at step 800.
-
Step 50
50
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E1EBF8
oklch(93.6% 0.021 254.9)
-
Step 200
200
#C8DBF4
oklch(88.5% 0.04 255.3)
-
Step 300
300
#A2C3EF
oklch(80.8% 0.072 255.7)
-
Step 400
400
#6FA3E7
oklch(70.7% 0.115 255.5)
-
Step 500
500
#478AE0
oklch(63.1% 0.147 255.7)
-
Step 600
600
#2672CE
oklch(55.6% 0.16 255.7)
-
Step 700
700
#185FB2
oklch(49% 0.148 255.7)
-
Step 800
800 (this color)
#21579A
oklch(45.8% 0.123 255.7)
-
Step 900
900
#1A4273
oklch(37.8% 0.095 255.2)
-
Step 950
950
#102743
oklch(27% 0.06 254.6)
#21579A with color blindness
Simulated with the Machado et al. (2009) model. ΔE is how far the color moves: below about 0.02 you would not notice a change.
| Vision | Seen as | Shift (ΔE) |
|---|---|---|
| Protanopia (no red cones) | #365D9D | 0.028 |
| Deuteranopia (no green cones) | #1F5299 | 0.015 |
| Tritanopia (no blue cones) | #006771 | 0.094 |
| Achromatopsia (no color) | #575757 | 0.123 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21579A
#21579A
oklch(45.8% 0.123 255.7)
- #764E00
#764E00
oklch(45.7% 0.096 75.1)
Analogous
Neighbouring hues, 30° either side.
Split complementary
The two hues beside the complement (150° and 210°).
Triadic
Three hues spaced 120° apart.
Palettes with this color
Curated palettes that contain a color within ΔE 0.04 (OKLab) of #21579A, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusk Blue #26538D ΔE 0.022
- Denim Blue #3B5B92 ΔE 0.032
- Light Navy Blue #2E5A88 ΔE 0.034
- Light Navy #155084 ΔE 0.041
- Deep Sea Blue #015482 ΔE 0.044
- Cobalt #1E488F ΔE 0.045
- Peacock Blue #016795 ΔE 0.049
- Dusky Blue #475F94 ΔE 0.049
Use #21579A in your product
Turn it into light and dark UI roles checked for contrast, then export to Tailwind v4, shadcn/ui, CSS or design tokens.