#1B5973
Closest named color: Petrol (#005F6A). oklch(43.7% 0.075 230.2), rgb(27, 89, 115).
Aa
White text reads best on this color (7.71:1).
About this color
#1B5973 is a dark, moderately saturated blue. In OKLCH its lightness is 44%, its chroma 0.075 and its hue 230°. Its hue sits on the cool side of the wheel. The nearest named color is Petrol (#005F6A), ΔE 0.029 away. White text reads best on it, at 7.71:1.
| Hue family | Blues |
| Lightness | dark (44%) |
| Chroma | moderately saturated (0.075) |
| Temperature | cool |
| Nearest name | Petrol (#005F6A) |
| Black text | 2.72:1 |
| White text | 7.71:1 |
Values
| HEX | #1B5973 |
| RGB | rgb(27, 89, 115) |
| HSL | hsl(198, 62%, 28%) |
| OKLCH | oklch(43.7% 0.075 230.2) |
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 #1B5973 | 7.71:1 | AAA | Lc -91.3 | Preferred for body text |
| Black text on #1B5973 | 2.72:1 | Fails | Lc 17.5 | Dividers and decoration only |
| #1B5973 text on white | 7.71:1 | AAA | Lc 86.5 | Fine for body text |
| #1B5973 text on black | 2.72:1 | Fails | Lc -15.6 | 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
#F2F6F9
oklch(97.1% 0.006 239.8)
-
Step 100
100
#E2ECF1
oklch(93.7% 0.013 228.9)
-
Step 200
200
#CADDE6
oklch(88.6% 0.024 227.8)
-
Step 300
300
#A5C6D8
oklch(80.8% 0.044 231.9)
-
Step 400
400
#72A9C4
oklch(70.7% 0.07 230.2)
-
Step 500
500
#4A93B5
oklch(63% 0.089 230.6)
-
Step 600
600
#267DA1
oklch(55.5% 0.097 230.3)
-
Step 700
700
#17698A
oklch(49% 0.09 230.8)
-
Step 800
800 (this color)
#1B5973
oklch(43.7% 0.075 230.2)
-
Step 900
900
#1B475B
oklch(37.7% 0.059 230.9)
-
Step 950
950
#112A35
oklch(27.1% 0.037 229)
#1B5973 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) | #4C5874 | 0.052 |
| Deuteranopia (no green cones) | #404F73 | 0.045 |
| Tritanopia (no blue cones) | #006062 | 0.043 |
| Achromatopsia (no color) | #535353 | 0.075 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B5973
#1B5973
oklch(43.7% 0.075 230.2)
- #73452A
#73452A
oklch(43.8% 0.075 50.2)
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 #1B5973, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Petrol #005F6A ΔE 0.029
- Deep Sea Blue #015482 ΔE 0.035
- YInMn Blue #415A77 ΔE 0.039
- Light Navy Blue #2E5A88 ΔE 0.040
- Light Navy #155084 ΔE 0.045
- Deep Teal #00555A ΔE 0.046
- Dusk Blue #26538D ΔE 0.052
- Dark Aqua #05696B ΔE 0.057
Use #1B5973 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.