#317B99
Closest named color: Cerulean (#457B9D). oklch(55% 0.086 228.2), rgb(49, 123, 153).
Aa
White text reads best on this color (4.74:1).
About this color
#317B99 is a medium-dark, moderately saturated teal or cyan. In OKLCH its lightness is 55%, its chroma 0.086 and its hue 228°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean (#457B9D), ΔE 0.019 away. White text reads best on it, at 4.74:1.
| Hue family | Teals and cyans |
| Lightness | medium-dark (55%) |
| Chroma | moderately saturated (0.086) |
| Temperature | cool |
| Nearest name | Cerulean (#457B9D) |
| Black text | 4.42:1 |
| White text | 4.74:1 |
Values
| HEX | #317B99 |
| RGB | rgb(49, 123, 153) |
| HSL | hsl(197, 51%, 40%) |
| OKLCH | oklch(55% 0.086 228.2) |
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 #317B99 | 4.74:1 | AA | Lc -78.1 | Fine for body text |
| Black text on #317B99 | 4.42:1 | AA large text | Lc 31.4 | Non-text elements, placeholder text |
| #317B99 text on white | 4.74:1 | AA | Lc 72.7 | Content text, not long reading |
| #317B99 text on black | 4.42:1 | AA large text | Lc -29.0 | 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
#F2F6F8
oklch(97.1% 0.005 228.8)
-
Step 100
100
#E3EBF0
oklch(93.5% 0.011 234.8)
-
Step 200
200
#CBDCE4
oklch(88.4% 0.021 227.6)
-
Step 300
300
#A8C6D5
oklch(80.9% 0.039 229.5)
-
Step 400
400
#78A9BF
oklch(70.8% 0.061 227.6)
-
Step 500
500
#5293AF
oklch(63.1% 0.079 227.9)
-
Step 600
600 (this color)
#317B99
oklch(55% 0.086 228.2)
-
Step 700
700
#256984
oklch(49% 0.079 228.2)
-
Step 800
800
#21566C
oklch(42.8% 0.066 228.7)
-
Step 900
900
#214757
oklch(37.7% 0.051 227.9)
-
Step 950
950
#142A33
oklch(27.1% 0.033 226.5)
#317B99 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) | #6B799B | 0.062 |
| Deuteranopia (no green cones) | #5D6E99 | 0.055 |
| Tritanopia (no blue cones) | #008485 | 0.052 |
| Achromatopsia (no color) | #737373 | 0.086 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #317B99
#317B99
oklch(55% 0.086 228.2)
- #9A6244
#9A6244
oklch(55% 0.085 48.5)
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 #317B99, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean #457B9D ΔE 0.019
- Ocean #017B92 ΔE 0.024
- Dull Blue #49759C ΔE 0.027
- Stormy Blue #507B9C ΔE 0.029
- Sea Blue #047495 ΔE 0.032
- Metallic Blue #4F738E ΔE 0.033
- Muted Blue #3B719F ΔE 0.034
- Teal Blue #01889F ΔE 0.038
Use #317B99 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.