#33437F
Closest named color: Cobalt (#1E488F). oklch(40.2% 0.103 270), rgb(51, 67, 127).
Aa
White text reads best on this color (9.33:1).
About this color
#33437F is a dark, moderately saturated blue. In OKLCH its lightness is 40%, its chroma 0.103 and its hue 270°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.033 away. White text reads best on it, at 9.33:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | moderately saturated (0.103) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.25:1 |
| White text | 9.33:1 |
Values
| HEX | #33437F |
| RGB | rgb(51, 67, 127) |
| HSL | hsl(227, 43%, 35%) |
| OKLCH | oklch(40.2% 0.103 270) |
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 #33437F | 9.33:1 | AAA | Lc -95.7 | Preferred for body text |
| Black text on #33437F | 2.25:1 | Fails | Lc 12.6 | Not readable |
| #33437F text on white | 9.33:1 | AAA | Lc 91.4 | Preferred for body text |
| #33437F text on black | 2.25:1 | Fails | Lc -11.0 | Not readable |
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 900.
-
Step 50
50
#F3F5FD
oklch(97.1% 0.011 274.9)
-
Step 100
100
#E4EAF9
oklch(93.7% 0.021 268.4)
-
Step 200
200
#CED8F6
oklch(88.4% 0.043 270.9)
-
Step 300
300
#ADBFF3
oklch(80.9% 0.076 269.8)
-
Step 400
400
#839CEE
oklch(70.8% 0.124 270.1)
-
Step 500
500
#6581E8
oklch(63.1% 0.158 270)
-
Step 600
600
#4E68D6
oklch(55.6% 0.171 270)
-
Step 700
700
#3F56B9
oklch(49.1% 0.158 269.8)
-
Step 800
800
#344796
oklch(42.8% 0.131 269.9)
-
Step 900
900 (this color)
#33437F
oklch(40.2% 0.103 270)
-
Step 950
950
#1A2446
oklch(27.1% 0.065 269.4)
#33437F 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) | #274A81 | 0.022 |
| Deuteranopia (no green cones) | #1D447E | 0.024 |
| Tritanopia (no blue cones) | #00505B | 0.090 |
| Achromatopsia (no color) | #474747 | 0.103 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #33437F
#33437F
oklch(40.2% 0.103 270)
- #594500
#594500
oklch(40% 0.082 89.8)
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 #33437F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.033
- Twilight Blue #0A437A ΔE 0.038
- Dark Slate Blue #483D8B ΔE 0.041
- Light Navy #155084 ΔE 0.042
- Dusk Blue #26538D ΔE 0.048
- Blueberry #464196 ΔE 0.048
- Deep Sea Blue #015482 ΔE 0.055
- Twilight #4E518B ΔE 0.061
Use #33437F 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.