#337AEF
Closest named color: Clear Blue (#247AFD). oklch(59.9% 0.19 260), rgb(51, 122, 239).
Aa
Black text reads best on this color (5.17:1).
About this color
#337AEF is a medium-dark, vivid blue. In OKLCH its lightness is 60%, its chroma 0.190 and its hue 260°. Its hue sits on the cool side of the wheel. The nearest named color is Clear Blue (#247AFD), ΔE 0.022 away. Black text reads best on it, at 5.17:1.
| Hue family | Blues |
| Lightness | medium-dark (60%) |
| Chroma | vivid (0.190) |
| Temperature | cool |
| Nearest name | Clear Blue (#247AFD) |
| Black text | 5.17:1 |
| White text | 4.06:1 |
Values
| HEX | #337AEF |
| RGB | rgb(51, 122, 239) |
| HSL | hsl(217, 85%, 57%) |
| OKLCH | oklch(59.9% 0.19 260) |
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 #337AEF | 4.06:1 | AA large text | Lc -72.8 | Content text, not long reading |
| Black text on #337AEF | 5.17:1 | AA | Lc 36.8 | Non-text elements, placeholder text |
| #337AEF text on white | 4.06:1 | AA large text | Lc 67.3 | Content text, not long reading |
| #337AEF text on black | 5.17:1 | AA | Lc -34.3 | 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 500.
-
Step 50
50
#F1F6FE
oklch(97.2% 0.012 259.8)
-
Step 100
100
#E0EBFC
oklch(93.7% 0.026 259)
-
Step 200
200
#C6DAFC
oklch(88.4% 0.052 261.1)
-
Step 300
300
#9EC2FD
oklch(80.9% 0.093 260.1)
-
Step 400
400
#68A0FC
oklch(70.8% 0.148 259.9)
-
Step 500
500 (this color)
#337AEF
oklch(59.9% 0.19 260)
-
Step 600
600
#196AE9
oklch(55.6% 0.207 260)
-
Step 700
700
#0957CB
oklch(49% 0.193 260)
-
Step 800
800
#0E48A4
oklch(42.7% 0.16 260.1)
-
Step 900
900
#143E82
oklch(37.8% 0.124 259.8)
-
Step 950
950
#0D254C
oklch(27% 0.078 259.7)
#337AEF 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) | #3387F3 | 0.033 |
| Deuteranopia (no green cones) | #0076ED | 0.024 |
| Tritanopia (no blue cones) | #0096A9 | 0.147 |
| Achromatopsia (no color) | #7E7E7E | 0.190 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #337AEF
#337AEF
oklch(59.9% 0.19 260)
- #A67600
#A67600
oklch(59.9% 0.124 80.2)
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 #337AEF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Clear Blue #247AFD ΔE 0.022
- Cerulean Blue #056EEE ΔE 0.040
- Royal Blue #4169E1 ΔE 0.045
- Cornflower #6A79F7 ΔE 0.056
- Dodger Blue #1E90FF ΔE 0.057
- Neon Blue #4361EE ΔE 0.059
- Dark Sky Blue #448EE4 ΔE 0.061
- Bright Blue #0165FC ΔE 0.063
Use #337AEF 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.