#337AA7
Closest named color: Nice Blue (#107AB0). oklch(55.5% 0.099 239.9), rgb(51, 122, 167).
Aa
White text reads best on this color (4.68:1).
About this color
#337AA7 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 55%, its chroma 0.099 and its hue 240°. Its hue sits on the cool side of the wheel. The nearest named color is Nice Blue (#107AB0), ΔE 0.021 away. White text reads best on it, at 4.68:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | moderately saturated (0.099) |
| Temperature | cool |
| Nearest name | Nice Blue (#107AB0) |
| Black text | 4.48:1 |
| White text | 4.68:1 |
Values
| HEX | #337AA7 |
| RGB | rgb(51, 122, 167) |
| HSL | hsl(203, 53%, 43%) |
| OKLCH | oklch(55.5% 0.099 239.9) |
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 #337AA7 | 4.68:1 | AA | Lc -77.7 | Fine for body text |
| Black text on #337AA7 | 4.48:1 | AA large text | Lc 31.8 | Non-text elements, placeholder text |
| #337AA7 text on white | 4.68:1 | AA | Lc 72.3 | Content text, not long reading |
| #337AA7 text on black | 4.48:1 | AA large text | Lc -29.4 | Dividers and decoration only |
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
#E2EBF2
oklch(93.5% 0.014 241)
-
Step 200
200
#CBDCE8
oklch(88.5% 0.025 238.4)
-
Step 300
300
#A7C5DB
oklch(80.8% 0.045 239.9)
-
Step 400
400
#77A7C9
oklch(70.7% 0.072 239.9)
-
Step 500
500
#5291BB
oklch(63.2% 0.091 239.6)
-
Step 600
600 (this color)
#337AA7
oklch(55.5% 0.099 239.9)
-
Step 700
700
#256790
oklch(49.2% 0.093 240)
-
Step 800
800
#215474
oklch(42.7% 0.076 239.6)
-
Step 900
900
#21465E
oklch(37.8% 0.059 239.4)
-
Step 950
950
#142937
oklch(27% 0.038 239.4)
#337AA7 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) | #657AA9 | 0.052 |
| Deuteranopia (no green cones) | #556FA6 | 0.042 |
| Tritanopia (no blue cones) | #008589 | 0.069 |
| Achromatopsia (no color) | #747474 | 0.099 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #337AA7
#337AA7
oklch(55.5% 0.099 239.9)
- #9D6431
#9D6431
oklch(55.5% 0.099 60.2)
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 #337AA7, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Nice Blue #107AB0 ΔE 0.021
- Flat Blue #3C73A8 ΔE 0.021
- Cerulean #457B9D ΔE 0.022
- Dull Blue #49759C ΔE 0.025
- Muted Blue #3B719F ΔE 0.026
- Stormy Blue #507B9C ΔE 0.031
- Steel Blue #4682B4 ΔE 0.035
- Ocean Blue #03719C ΔE 0.040
Use #337AA7 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.