#01559F
Closest named color: Dusk Blue (#26538D). oklch(45% 0.139 253.1), rgb(1, 85, 159).
Aa
White text reads best on this color (7.49:1).
About this color
#01559F is a medium-dark, moderately saturated blue. In OKLCH its lightness is 45%, its chroma 0.139 and its hue 253°. Its hue sits on the cool side of the wheel. The nearest named color is Dusk Blue (#26538D), ΔE 0.032 away. White text reads best on it, at 7.49:1.
| Hue family | Blues |
| Lightness | medium-dark (45%) |
| Chroma | moderately saturated (0.139) |
| Temperature | cool |
| Nearest name | Dusk Blue (#26538D) |
| Black text | 2.80:1 |
| White text | 7.49:1 |
Values
| HEX | #01559F |
| RGB | rgb(1, 85, 159) |
| HSL | hsl(208, 99%, 31%) |
| OKLCH | oklch(45% 0.139 253.1) |
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 #01559F | 7.49:1 | AAA | Lc -90.2 | Preferred for body text |
| Black text on #01559F | 2.80:1 | Fails | Lc 18.7 | Dividers and decoration only |
| #01559F text on white | 7.49:1 | AAA | Lc 85.4 | Fine for body text |
| #01559F text on black | 2.80:1 | Fails | Lc -16.7 | 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 800.
-
Step 50
50
#F0F6FD
oklch(97.1% 0.011 252.1)
-
Step 100
100
#DFEBFA
oklch(93.6% 0.024 254)
-
Step 200
200
#C5DCF7
oklch(88.6% 0.045 252.5)
-
Step 300
300
#9CC4F4
oklch(80.9% 0.081 253.3)
-
Step 400
400
#63A4EF
oklch(70.7% 0.129 253.1)
-
Step 500
500
#318BEA
oklch(63.2% 0.166 253.1)
-
Step 600
600
#0073D4
oklch(55.6% 0.172 253.1)
-
Step 700
700
#0060B3
oklch(49% 0.152 253.2)
-
Step 800
800 (this color)
#01559F
oklch(45% 0.139 253.1)
-
Step 900
900
#0A4279
oklch(37.8% 0.108 253.1)
-
Step 950
950
#092747
oklch(27% 0.069 253.1)
#01559F 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) | #2B5CA2 | 0.033 |
| Deuteranopia (no green cones) | #004F9E | 0.017 |
| Tritanopia (no blue cones) | #006772 | 0.102 |
| Achromatopsia (no color) | #555555 | 0.139 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #01559F
#01559F
oklch(45% 0.139 253.1)
- #754B00
#754B00
oklch(45% 0.096 72.6)
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 #01559F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusk Blue #26538D ΔE 0.032
- Cobalt #1E488F ΔE 0.041
- Light Navy #155084 ΔE 0.044
- Deep Sea Blue #015482 ΔE 0.048
- Light Navy Blue #2E5A88 ΔE 0.049
- Denim Blue #3B5B92 ΔE 0.050
- Peacock Blue #016795 ΔE 0.058
- Dusky Blue #475F94 ΔE 0.067
Use #01559F 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.