#437BD0
Closest named color: Windows Blue (#3778BF). oklch(58.7% 0.144 258.6), rgb(67, 123, 208).
Aa
Black text reads best on this color (4.98:1).
About this color
#437BD0 is a medium-dark, vivid blue. In OKLCH its lightness is 59%, its chroma 0.144 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.030 away. Black text reads best on it, at 4.98:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | vivid (0.144) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.98:1 |
| White text | 4.21:1 |
Values
| HEX | #437BD0 |
| RGB | rgb(67, 123, 208) |
| HSL | hsl(216, 60%, 54%) |
| OKLCH | oklch(58.7% 0.144 258.6) |
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 #437BD0 | 4.21:1 | AA large text | Lc -74.3 | Content text, not long reading |
| Black text on #437BD0 | 4.98:1 | AA | Lc 35.3 | Non-text elements, placeholder text |
| #437BD0 text on white | 4.21:1 | AA large text | Lc 68.8 | Content text, not long reading |
| #437BD0 text on black | 4.98:1 | AA | Lc -32.9 | 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
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E2EAF7
oklch(93.5% 0.02 260.2)
-
Step 200
200
#CBDAF1
oklch(88.4% 0.036 258.9)
-
Step 300
300
#A8C2EB
oklch(80.9% 0.065 259.4)
-
Step 400
400
#79A2E1
oklch(70.8% 0.103 258.8)
-
Step 500
500
#5589D8
oklch(63% 0.132 258.5)
-
Step 600
600 (this color)
#437BD0
oklch(58.7% 0.144 258.6)
-
Step 700
700
#2C5FAB
oklch(49.1% 0.133 258.4)
-
Step 800
800
#264E8A
oklch(42.7% 0.11 258.4)
-
Step 900
900
#23416F
oklch(37.7% 0.087 258.7)
-
Step 950
950
#152641
oklch(26.9% 0.056 259.3)
#437BD0 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) | #5482D3 | 0.027 |
| Deuteranopia (no green cones) | #3D75CE | 0.018 |
| Tritanopia (no blue cones) | #008F9B | 0.116 |
| Achromatopsia (no color) | #7B7B7B | 0.144 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #437BD0
#437BD0
oklch(58.7% 0.144 258.6)
- #A37200
#A37200
oklch(58.7% 0.122 78.7)
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 #437BD0, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.030
- Water Blue #0E87CC ΔE 0.041
- Cool Blue #4984B8 ΔE 0.050
- Steel Blue #4682B4 ΔE 0.052
- Dark Sky Blue #448EE4 ΔE 0.055
- Royal Blue #4169E1 ΔE 0.057
- Nice Blue #107AB0 ΔE 0.061
- Soft Blue #6488EA ΔE 0.064
Use #437BD0 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.