#337DD7
Closest named color: Water Blue (#0E87CC). oklch(59% 0.156 255.3), rgb(51, 125, 215).
Aa
Black text reads best on this color (5.05:1).
About this color
#337DD7 is a medium-dark, vivid blue. In OKLCH its lightness is 59%, its chroma 0.156 and its hue 255°. Its hue sits on the cool side of the wheel. The nearest named color is Water Blue (#0E87CC), ΔE 0.037 away. Black text reads best on it, at 5.05:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | vivid (0.156) |
| Temperature | cool |
| Nearest name | Water Blue (#0E87CC) |
| Black text | 5.05:1 |
| White text | 4.15:1 |
Values
| HEX | #337DD7 |
| RGB | rgb(51, 125, 215) |
| HSL | hsl(213, 67%, 52%) |
| OKLCH | oklch(59% 0.156 255.3) |
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 #337DD7 | 4.15:1 | AA large text | Lc -73.7 | Content text, not long reading |
| Black text on #337DD7 | 5.05:1 | AA | Lc 35.9 | Non-text elements, placeholder text |
| #337DD7 text on white | 4.15:1 | AA large text | Lc 68.2 | Content text, not long reading |
| #337DD7 text on black | 5.05:1 | AA | Lc -33.5 | 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
#C8DBF3
oklch(88.5% 0.039 254.3)
-
Step 300
300
#A3C3EE
oklch(80.9% 0.07 255.9)
-
Step 400
400
#70A3E5
oklch(70.7% 0.112 255.3)
-
Step 500
500
#488BDE
oklch(63.2% 0.143 255)
-
Step 600
600 (this color)
#337DD7
oklch(59% 0.156 255.3)
-
Step 700
700
#1A60B0
oklch(49.2% 0.144 255.1)
-
Step 800
800
#184E8F
oklch(42.6% 0.121 255.6)
-
Step 900
900
#1B4272
oklch(37.8% 0.093 255.2)
-
Step 950
950
#112743
oklch(27.1% 0.059 255.4)
#337DD7 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) | #5184DB | 0.035 |
| Deuteranopia (no green cones) | #3475D5 | 0.021 |
| Tritanopia (no blue cones) | #00929F | 0.119 |
| Achromatopsia (no color) | #7C7C7C | 0.156 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #337DD7
#337DD7
oklch(59% 0.156 255.3)
- #A77100
#A77100
oklch(59% 0.124 75.7)
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 #337DD7, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Water Blue #0E87CC ΔE 0.037
- Windows Blue #3778BF ΔE 0.037
- Dark Sky Blue #448EE4 ΔE 0.052
- Royal Blue #4169E1 ΔE 0.055
- Cool Blue #4984B8 ΔE 0.058
- Clear Blue #247AFD ΔE 0.059
- Steel Blue #4682B4 ΔE 0.060
- Cerulean Blue #056EEE ΔE 0.060
Use #337DD7 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.