#155A9E
Closest named color: Dusk Blue (#26538D). oklch(46.4% 0.128 252.6), rgb(21, 90, 158).
Aa
White text reads best on this color (7.02:1).
About this color
#155A9E is a medium-dark, moderately saturated blue. In OKLCH its lightness is 46%, its chroma 0.128 and its hue 253°. Its hue sits on the cool side of the wheel. The nearest named color is Dusk Blue (#26538D), ΔE 0.031 away. White text reads best on it, at 7.02:1.
| Hue family | Blues |
| Lightness | medium-dark (46%) |
| Chroma | moderately saturated (0.128) |
| Temperature | cool |
| Nearest name | Dusk Blue (#26538D) |
| Black text | 2.98:1 |
| White text | 7.02:1 |
Values
| HEX | #155A9E |
| RGB | rgb(21, 90, 158) |
| HSL | hsl(210, 77%, 35%) |
| OKLCH | oklch(46.4% 0.128 252.6) |
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 #155A9E | 7.02:1 | AAA | Lc -88.8 | Fine for body text |
| Black text on #155A9E | 2.98:1 | Fails | Lc 20.2 | Dividers and decoration only |
| #155A9E text on white | 7.02:1 | AAA | Lc 83.9 | Fine for body text |
| #155A9E text on black | 2.98:1 | Fails | Lc -18.1 | 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 700.
-
Step 50
50
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E2EBF6
oklch(93.7% 0.018 253.3)
-
Step 200
200
#CADBF0
oklch(88.5% 0.034 253.7)
-
Step 300
300
#A5C4E8
oklch(81% 0.061 252.4)
-
Step 400
400
#73A4DD
oklch(70.7% 0.099 252.9)
-
Step 500
500
#4C8CD4
oklch(63% 0.128 252.9)
-
Step 600
600
#2D75C1
oklch(55.6% 0.138 252.7)
-
Step 700
700 (this color)
#155A9E
oklch(46.4% 0.128 252.6)
-
Step 800
800
#1C5087
oklch(42.7% 0.106 252.8)
-
Step 900
900
#1D436C
oklch(37.7% 0.083 252.4)
-
Step 950
950
#12273F
oklch(26.9% 0.053 253.1)
#155A9E 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) | #375FA1 | 0.032 |
| Deuteranopia (no green cones) | #1E539D | 0.019 |
| Tritanopia (no blue cones) | #006A74 | 0.094 |
| Achromatopsia (no color) | #595959 | 0.128 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #155A9E
#155A9E
oklch(46.4% 0.128 252.6)
- #7A4F00
#7A4F00
oklch(46.4% 0.099 73.2)
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 #155A9E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusk Blue #26538D ΔE 0.031
- Denim Blue #3B5B92 ΔE 0.036
- Light Navy Blue #2E5A88 ΔE 0.039
- Peacock Blue #016795 ΔE 0.043
- Light Navy #155084 ΔE 0.048
- Deep Sea Blue #015482 ΔE 0.049
- Dusky Blue #475F94 ΔE 0.052
- Cobalt #1E488F ΔE 0.053
Use #155A9E 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.