#337CDA
Closest named color: Windows Blue (#3778BF). oklch(58.9% 0.161 256.3), rgb(51, 124, 218).
Aa
Black text reads best on this color (5.03:1).
About this color
#337CDA is a medium-dark, vivid blue. In OKLCH its lightness is 59%, its chroma 0.161 and its hue 256°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.041 away. Black text reads best on it, at 5.03:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | vivid (0.161) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 5.03:1 |
| White text | 4.16:1 |
Values
| HEX | #337CDA |
| RGB | rgb(51, 124, 218) |
| HSL | hsl(214, 69%, 53%) |
| OKLCH | oklch(58.9% 0.161 256.3) |
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 #337CDA | 4.16:1 | AA large text | Lc -73.8 | Content text, not long reading |
| Black text on #337CDA | 5.03:1 | AA | Lc 35.8 | Non-text elements, placeholder text |
| #337CDA text on white | 4.16:1 | AA large text | Lc 68.3 | Content text, not long reading |
| #337CDA text on black | 5.03:1 | AA | Lc -33.4 | 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
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E1EBF8
oklch(93.6% 0.021 254.9)
-
Step 200
200
#C8DBF4
oklch(88.5% 0.04 255.3)
-
Step 300
300
#A3C3EF
oklch(80.9% 0.072 256.4)
-
Step 400
400
#70A3E8
oklch(70.8% 0.115 256.2)
-
Step 500
500
#488AE1
oklch(63.2% 0.148 256.2)
-
Step 600
600 (this color)
#337CDA
oklch(58.9% 0.161 256.3)
-
Step 700
700
#1A5FB3
oklch(49.2% 0.149 256.2)
-
Step 800
800
#194E91
oklch(42.8% 0.124 256.3)
-
Step 900
900
#1B4174
oklch(37.7% 0.098 256.7)
-
Step 950
950
#112744
oklch(27.1% 0.061 256.1)
#337CDA 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) | #4D84DE | 0.033 |
| Deuteranopia (no green cones) | #2D75D8 | 0.020 |
| Tritanopia (no blue cones) | #0092A0 | 0.123 |
| Achromatopsia (no color) | #7C7C7C | 0.161 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #337CDA
#337CDA
oklch(58.9% 0.161 256.3)
- #A67100
#A67100
oklch(58.9% 0.124 76.3)
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 #337CDA, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.041
- Water Blue #0E87CC ΔE 0.042
- Royal Blue #4169E1 ΔE 0.051
- Dark Sky Blue #448EE4 ΔE 0.053
- Clear Blue #247AFD ΔE 0.054
- Cerulean Blue #056EEE ΔE 0.055
- Cool Blue #4984B8 ΔE 0.064
- Soft Blue #6488EA ΔE 0.064
Use #337CDA 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.