#437D99
Closest named color: Cerulean (#457B9D). oklch(56.2% 0.075 231.1), rgb(67, 125, 153).
Aa
Black text reads best on this color (4.63:1).
About this color
#437D99 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 56%, its chroma 0.075 and its hue 231°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean (#457B9D), ΔE 0.010 away. Black text reads best on it, at 4.63:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | moderately saturated (0.075) |
| Temperature | cool |
| Nearest name | Cerulean (#457B9D) |
| Black text | 4.63:1 |
| White text | 4.53:1 |
Values
| HEX | #437D99 |
| RGB | rgb(67, 125, 153) |
| HSL | hsl(200, 39%, 43%) |
| OKLCH | oklch(56.2% 0.075 231.1) |
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 #437D99 | 4.53:1 | AA | Lc -76.8 | Fine for body text |
| Black text on #437D99 | 4.63:1 | AA | Lc 32.7 | Non-text elements, placeholder text |
| #437D99 text on white | 4.53:1 | AA | Lc 71.3 | Content text, not long reading |
| #437D99 text on black | 4.63:1 | AA | Lc -30.3 | Non-text elements, placeholder text |
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 600.
-
Step 50
50
#F3F6F8
oklch(97.1% 0.004 236.5)
-
Step 100
100
#E4EBEF
oklch(93.6% 0.009 232.4)
-
Step 200
200
#CDDCE3
oklch(88.5% 0.019 227.3)
-
Step 300
300
#ACC5D3
oklch(80.9% 0.034 232.3)
-
Step 400
400
#7FA7BC
oklch(70.7% 0.053 231.3)
-
Step 500
500
#5D91AC
oklch(63.1% 0.069 232)
-
Step 600
600 (this color)
#437D99
oklch(56.2% 0.075 231.1)
-
Step 700
700
#336881
oklch(49.2% 0.069 230.9)
-
Step 800
800
#2B5569
oklch(42.8% 0.057 230.8)
-
Step 900
900
#274655
oklch(37.7% 0.045 230.6)
-
Step 950
950
#182932
oklch(27% 0.028 232.3)
#437D99 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) | #6F7B9A | 0.051 |
| Deuteranopia (no green cones) | #637299 | 0.046 |
| Tritanopia (no blue cones) | #008586 | 0.055 |
| Achromatopsia (no color) | #767676 | 0.075 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #437D99
#437D99
oklch(56.2% 0.075 231.1)
- #98684C
#98684C
oklch(56.1% 0.074 51)
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 #437D99, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean #457B9D ΔE 0.010
- Stormy Blue #507B9C ΔE 0.015
- Dull Blue #49759C ΔE 0.026
- Metallic Blue #4F738E ΔE 0.030
- Ocean #017B92 ΔE 0.038
- Grey Blue #647D8E ΔE 0.039
- Teal Blue #01889F ΔE 0.039
- Muted Blue #3B719F ΔE 0.041
Use #437D99 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.