#1F5571
Closest named color: Deep Sea Blue (#015482). oklch(42.7% 0.073 234.9), rgb(31, 85, 113).
Aa
White text reads best on this color (8.08:1).
About this color
#1F5571 is a dark, moderately saturated blue. In OKLCH its lightness is 43%, its chroma 0.073 and its hue 235°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sea Blue (#015482), ΔE 0.032 away. White text reads best on it, at 8.08:1.
| Hue family | Blues |
| Lightness | dark (43%) |
| Chroma | moderately saturated (0.073) |
| Temperature | cool |
| Nearest name | Deep Sea Blue (#015482) |
| Black text | 2.59:1 |
| White text | 8.08:1 |
Values
| HEX | #1F5571 |
| RGB | rgb(31, 85, 113) |
| HSL | hsl(200, 57%, 28%) |
| OKLCH | oklch(42.7% 0.073 234.9) |
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 #1F5571 | 8.08:1 | AAA | Lc -92.4 | Preferred for body text |
| Black text on #1F5571 | 2.59:1 | Fails | Lc 16.2 | Dividers and decoration only |
| #1F5571 text on white | 8.08:1 | AAA | Lc 87.8 | Fine for body text |
| #1F5571 text on black | 2.59:1 | Fails | Lc -14.4 | Not readable |
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
#E2EBF1
oklch(93.5% 0.013 236.6)
-
Step 200
200
#CBDCE7
oklch(88.5% 0.024 236)
-
Step 300
300
#A7C6D8
oklch(81% 0.042 233.5)
-
Step 400
400
#76A8C5
oklch(70.7% 0.068 234.5)
-
Step 500
500
#5092B7
oklch(63.1% 0.088 235)
-
Step 600
600
#317CA3
oklch(55.7% 0.095 234.9)
-
Step 700
700
#22688B
oklch(49.1% 0.088 234.7)
-
Step 800
800 (this color)
#1F5571
oklch(42.7% 0.073 234.9)
-
Step 900
900
#20465B
oklch(37.6% 0.056 235.2)
-
Step 950
950
#142935
oklch(26.9% 0.035 235.2)
#1F5571 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) | #475472 | 0.044 |
| Deuteranopia (no green cones) | #3C4C71 | 0.038 |
| Tritanopia (no blue cones) | #005C5E | 0.047 |
| Achromatopsia (no color) | #505050 | 0.073 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1F5571
#1F5571
oklch(42.7% 0.073 234.9)
- #6D4325
#6D4325
oklch(42.5% 0.073 54.9)
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 #1F5571, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sea Blue #015482 ΔE 0.032
- Petrol #005F6A ΔE 0.038
- Light Navy #155084 ΔE 0.039
- YInMn Blue #415A77 ΔE 0.042
- Light Navy Blue #2E5A88 ΔE 0.043
- Deep Teal #00555A ΔE 0.045
- Dusk Blue #26538D ΔE 0.050
- Dark Grey Blue #29465B ΔE 0.052
Use #1F5571 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.