#1B5B9D
Closest named color: Dusk Blue (#26538D). oklch(46.7% 0.124 252.9), rgb(27, 91, 157).
Aa
White text reads best on this color (6.93:1).
About this color
#1B5B9D is a medium-dark, moderately saturated blue. In OKLCH its lightness is 47%, its chroma 0.124 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 6.93:1.
| Hue family | Blues |
| Lightness | medium-dark (47%) |
| Chroma | moderately saturated (0.124) |
| Temperature | cool |
| Nearest name | Dusk Blue (#26538D) |
| Black text | 3.02:1 |
| White text | 6.93:1 |
Values
| HEX | #1B5B9D |
| RGB | rgb(27, 91, 157) |
| HSL | hsl(210, 71%, 36%) |
| OKLCH | oklch(46.7% 0.124 252.9) |
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 #1B5B9D | 6.93:1 | AA | Lc -88.5 | Fine for body text |
| Black text on #1B5B9D | 3.02:1 | AA large text | Lc 20.5 | Dividers and decoration only |
| #1B5B9D text on white | 6.93:1 | AA | Lc 83.6 | Fine for body text |
| #1B5B9D text on black | 3.02:1 | AA large text | Lc -18.4 | 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 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
#CADBEF
oklch(88.5% 0.033 252.5)
-
Step 300
300
#A6C4E7
oklch(81% 0.059 252.5)
-
Step 400
400
#75A4DB
oklch(70.7% 0.096 253)
-
Step 500
500
#4F8CD2
oklch(63% 0.124 253.2)
-
Step 600
600
#3175BF
oklch(55.6% 0.134 253)
-
Step 700
700 (this color)
#1B5B9D
oklch(46.7% 0.124 252.9)
-
Step 800
800
#1F5085
oklch(42.6% 0.103 252.9)
-
Step 900
900
#1F436B
oklch(37.7% 0.08 252.8)
-
Step 950
950
#13273F
oklch(26.9% 0.052 254)
#1B5B9D 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) | #3A60A0 | 0.032 |
| Deuteranopia (no green cones) | #23549C | 0.019 |
| Tritanopia (no blue cones) | #006B74 | 0.093 |
| Achromatopsia (no color) | #5A5A5A | 0.124 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B5B9D
#1B5B9D
oklch(46.7% 0.124 252.9)
- #7B5000
#7B5000
oklch(46.8% 0.099 73.6)
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 #1B5B9D, 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 0.031
- Light Navy Blue #2E5A88 ΔE 0.035
- Peacock Blue #016795 ΔE 0.040
- Dusky Blue #475F94 ΔE 0.047
- Denim #3B638C ΔE 0.049
- Light Navy #155084 ΔE 0.049
- Deep Sea Blue #015482 ΔE 0.050
Use #1B5B9D 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.