#287C9F
Closest named color: Cerulean (#457B9D). oklch(55.2% 0.095 230.1), rgb(40, 124, 159).
Aa
White text reads best on this color (4.69:1).
About this color
#287C9F is a medium-dark, moderately saturated blue. In OKLCH its lightness is 55%, its chroma 0.095 and its hue 230°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean (#457B9D), ΔE 0.022 away. White text reads best on it, at 4.69:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | moderately saturated (0.095) |
| Temperature | cool |
| Nearest name | Cerulean (#457B9D) |
| Black text | 4.47:1 |
| White text | 4.69:1 |
Values
| HEX | #287C9F |
| RGB | rgb(40, 124, 159) |
| HSL | hsl(198, 60%, 39%) |
| OKLCH | oklch(55.2% 0.095 230.1) |
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 #287C9F | 4.69:1 | AA | Lc -77.7 | Fine for body text |
| Black text on #287C9F | 4.47:1 | AA large text | Lc 31.8 | Non-text elements, placeholder text |
| #287C9F text on white | 4.69:1 | AA | Lc 72.3 | Content text, not long reading |
| #287C9F text on black | 4.47:1 | 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
#E2ECF1
oklch(93.7% 0.013 228.9)
-
Step 200
200
#CADCE6
oklch(88.4% 0.024 231.9)
-
Step 300
300
#A5C6D7
oklch(80.8% 0.043 230.3)
-
Step 400
400
#73A9C3
oklch(70.7% 0.068 229.7)
-
Step 500
500
#4B93B4
oklch(63% 0.087 230.1)
-
Step 600
600 (this color)
#287C9F
oklch(55.2% 0.095 230.1)
-
Step 700
700
#1A6989
oklch(49% 0.089 230.4)
-
Step 800
800
#1A566F
oklch(42.7% 0.073 230)
-
Step 900
900
#1C475A
oklch(37.7% 0.057 230)
-
Step 950
950
#122A35
oklch(27.1% 0.036 229.8)
#287C9F 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) | #6A7AA1 | 0.065 |
| Deuteranopia (no green cones) | #5A6F9F | 0.056 |
| Tritanopia (no blue cones) | #008688 | 0.056 |
| Achromatopsia (no color) | #747474 | 0.095 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #287C9F
#287C9F
oklch(55.2% 0.095 230.1)
- #9E613D
#9E613D
oklch(55.3% 0.094 50.4)
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 #287C9F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean #457B9D ΔE 0.022
- Ocean #017B92 ΔE 0.026
- Nice Blue #107AB0 ΔE 0.030
- Dull Blue #49759C ΔE 0.030
- Sea Blue #047495 ΔE 0.032
- Stormy Blue #507B9C ΔE 0.033
- Muted Blue #3B719F ΔE 0.033
- Flat Blue #3C73A8 ΔE 0.035
Use #287C9F 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.