#1B599D
Closest named color: Dusk Blue (#26538D). oklch(46.3% 0.126 254), rgb(27, 89, 157).
Aa
White text reads best on this color (7.08:1).
About this color
#1B599D is a medium-dark, moderately saturated blue. In OKLCH its lightness is 46%, its chroma 0.126 and its hue 254°. Its hue sits on the cool side of the wheel. The nearest named color is Dusk Blue (#26538D), ΔE 0.029 away. White text reads best on it, at 7.08:1.
| Hue family | Blues |
| Lightness | medium-dark (46%) |
| Chroma | moderately saturated (0.126) |
| Temperature | cool |
| Nearest name | Dusk Blue (#26538D) |
| Black text | 2.96:1 |
| White text | 7.08:1 |
Values
| HEX | #1B599D |
| RGB | rgb(27, 89, 157) |
| HSL | hsl(211, 71%, 36%) |
| OKLCH | oklch(46.3% 0.126 254) |
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 #1B599D | 7.08:1 | AAA | Lc -89.1 | Fine for body text |
| Black text on #1B599D | 2.96:1 | Fails | Lc 19.9 | Dividers and decoration only |
| #1B599D text on white | 7.08:1 | AAA | Lc 84.1 | Fine for body text |
| #1B599D text on black | 2.96:1 | Fails | Lc -17.8 | 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
#A6C3E8
oklch(80.8% 0.061 254.7)
-
Step 400
400
#75A4DD
oklch(70.8% 0.098 253.8)
-
Step 500
500
#508CD3
oklch(63.1% 0.125 253.8)
-
Step 600
600
#3274C0
oklch(55.5% 0.136 254.1)
-
Step 700
700 (this color)
#1B599D
oklch(46.3% 0.126 254)
-
Step 800
800
#205087
oklch(42.8% 0.105 254)
-
Step 900
900
#20436C
oklch(37.8% 0.081 253.8)
-
Step 950
950
#13273F
oklch(26.9% 0.052 254)
#1B599D 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) | #375FA0 | 0.031 |
| Deuteranopia (no green cones) | #1E539C | 0.017 |
| Tritanopia (no blue cones) | #006973 | 0.095 |
| Achromatopsia (no color) | #585858 | 0.127 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B599D
#1B599D
oklch(46.3% 0.126 254)
- #794F00
#794F00
oklch(46.3% 0.098 74)
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 #1B599D, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusk Blue #26538D ΔE 0.029
- Denim Blue #3B5B92 ΔE 0.034
- Light Navy Blue #2E5A88 ΔE 0.037
- Peacock Blue #016795 ΔE 0.045
- Light Navy #155084 ΔE 0.046
- Deep Sea Blue #015482 ΔE 0.048
- Dusky Blue #475F94 ΔE 0.050
- Cobalt #1E488F ΔE 0.051
Use #1B599D 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.