#437CA5
Closest named color: Cerulean (#457B9D). oklch(56.5% 0.088 241.8), rgb(67, 124, 165).
Aa
Black text reads best on this color (4.66:1).
About this color
#437CA5 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 57%, its chroma 0.088 and its hue 242°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean (#457B9D), ΔE 0.012 away. Black text reads best on it, at 4.66:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | moderately saturated (0.088) |
| Temperature | cool |
| Nearest name | Cerulean (#457B9D) |
| Black text | 4.66:1 |
| White text | 4.50:1 |
Values
| HEX | #437CA5 |
| RGB | rgb(67, 124, 165) |
| HSL | hsl(205, 42%, 45%) |
| OKLCH | oklch(56.5% 0.088 241.8) |
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 #437CA5 | 4.50:1 | AA | Lc -76.6 | Fine for body text |
| Black text on #437CA5 | 4.66:1 | AA | Lc 33.0 | Non-text elements, placeholder text |
| #437CA5 text on white | 4.50:1 | AA | Lc 71.1 | Content text, not long reading |
| #437CA5 text on black | 4.66:1 | AA | Lc -30.6 | 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
#F2F6F9
oklch(97.1% 0.006 239.8)
-
Step 100
100
#E3EBF1
oklch(93.6% 0.012 239.9)
-
Step 200
200
#CDDBE7
oklch(88.4% 0.022 243.8)
-
Step 300
300
#ABC4D8
oklch(80.8% 0.039 242.2)
-
Step 400
400
#7EA6C5
oklch(70.7% 0.063 242)
-
Step 500
500
#5C90B6
oklch(63.2% 0.08 241.3)
-
Step 600
600 (this color)
#437CA5
oklch(56.5% 0.088 241.8)
-
Step 700
700
#32668B
oklch(49.1% 0.082 242)
-
Step 800
800
#2A5371
oklch(42.6% 0.068 242.4)
-
Step 900
900
#27455B
oklch(37.7% 0.052 241.8)
-
Step 950
950
#172835
oklch(26.8% 0.033 242.4)
#437CA5 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) | #6A7CA7 | 0.045 |
| Deuteranopia (no green cones) | #5D72A4 | 0.037 |
| Tritanopia (no blue cones) | #00868A | 0.068 |
| Achromatopsia (no color) | #777777 | 0.088 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #437CA5
#437CA5
oklch(56.5% 0.088 241.8)
- #9B6A3D
#9B6A3D
oklch(56.6% 0.087 62.1)
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 #437CA5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean #457B9D ΔE 0.012
- Stormy Blue #507B9C ΔE 0.018
- Dull Blue #49759C ΔE 0.021
- Steel Blue #4682B4 ΔE 0.027
- Flat Blue #3C73A8 ΔE 0.030
- Off Blue #5684AE ΔE 0.034
- Muted Blue #3B719F ΔE 0.034
- Cool Blue #4984B8 ΔE 0.035
Use #437CA5 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.