#437CB1
Closest named color: Steel Blue (#4682B4). oklch(57.1% 0.102 248.5), rgb(67, 124, 177).
Aa
Black text reads best on this color (4.75:1).
About this color
#437CB1 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 57%, its chroma 0.102 and its hue 248°. Its hue sits on the cool side of the wheel. The nearest named color is Steel Blue (#4682B4), ΔE 0.018 away. Black text reads best on it, at 4.75:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | moderately saturated (0.102) |
| Temperature | cool |
| Nearest name | Steel Blue (#4682B4) |
| Black text | 4.75:1 |
| White text | 4.41:1 |
Values
| HEX | #437CB1 |
| RGB | rgb(67, 124, 177) |
| HSL | hsl(209, 45%, 48%) |
| OKLCH | oklch(57.1% 0.102 248.5) |
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 #437CB1 | 4.41:1 | AA large text | Lc -75.9 | Fine for body text |
| Black text on #437CB1 | 4.75:1 | AA | Lc 33.7 | Non-text elements, placeholder text |
| #437CB1 text on white | 4.41:1 | AA large text | Lc 70.4 | Content text, not long reading |
| #437CB1 text on black | 4.75:1 | AA | Lc -31.2 | 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
#E3EBF3
oklch(93.6% 0.014 248)
-
Step 200
200
#CDDBEA
oklch(88.5% 0.026 250)
-
Step 300
300
#AAC4DE
oklch(80.9% 0.046 248.4)
-
Step 400
400
#7CA5CD
oklch(70.7% 0.074 248.3)
-
Step 500
500
#5A8EC0
oklch(63.1% 0.094 248.6)
-
Step 600
600 (this color)
#437CB1
oklch(57.1% 0.102 248.5)
-
Step 700
700
#306494
oklch(49% 0.095 248.7)
-
Step 800
800
#295278
oklch(42.7% 0.079 248.5)
-
Step 900
900
#264461
oklch(37.7% 0.062 249)
-
Step 950
950
#172839
oklch(27.1% 0.039 249.5)
#437CB1 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) | #657EB3 | 0.039 |
| Deuteranopia (no green cones) | #5673B0 | 0.030 |
| Tritanopia (no blue cones) | #00888F | 0.080 |
| Achromatopsia (no color) | #787878 | 0.102 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #437CB1
#437CB1
oklch(57.1% 0.102 248.5)
- #9F6B2C
#9F6B2C
oklch(57.1% 0.102 68)
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 #437CB1, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Steel Blue #4682B4 ΔE 0.018
- Cool Blue #4984B8 ΔE 0.025
- Windows Blue #3778BF ΔE 0.029
- Flat Blue #3C73A8 ΔE 0.029
- Cerulean #457B9D ΔE 0.031
- Nice Blue #107AB0 ΔE 0.032
- Off Blue #5684AE ΔE 0.033
- Stormy Blue #507B9C ΔE 0.034
Use #437CB1 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.