#1B1537
Closest named color: Rich Black (#0D1B2A). oklch(22.4% 0.064 288.3), rgb(27, 21, 55).
Aa
White text reads best on this color (17.36:1).
About this color
#1B1537 is a very dark, muted purple. In OKLCH its lightness is 22%, its chroma 0.064 and its hue 288°. Its hue sits on the cool side of the wheel. The nearest named color is Rich Black (#0D1B2A), ΔE 0.042 away. White text reads best on it, at 17.36:1.
| Hue family | Purples |
| Lightness | very dark (22%) |
| Chroma | muted (0.064) |
| Temperature | cool |
| Nearest name | Rich Black (#0D1B2A) |
| Black text | 1.20:1 |
| White text | 17.36:1 |
Values
| HEX | #1B1537 |
| RGB | rgb(27, 21, 55) |
| HSL | hsl(251, 45%, 15%) |
| OKLCH | oklch(22.4% 0.064 288.3) |
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 #1B1537 | 17.36:1 | AAA | Lc -106.4 | Preferred for body text |
| Black text on #1B1537 | 1.20:1 | Fails | Lc 0.0 | Not readable |
| #1B1537 text on white | 17.36:1 | AAA | Lc 104.1 | Preferred for body text |
| #1B1537 text on black | 1.20:1 | Fails | Lc 0.0 | 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 950.
-
Step 50
50
#F5F4FC
oklch(97% 0.011 292)
-
Step 100
100
#E9E8F8
oklch(93.6% 0.021 288.9)
-
Step 200
200
#D7D5F4
oklch(88.4% 0.042 288.5)
-
Step 300
300
#BEB9EF
oklch(80.8% 0.076 288.8)
-
Step 400
400
#9D94E7
oklch(70.7% 0.12 287.9)
-
Step 500
500
#8777E0
oklch(63.1% 0.154 288.2)
-
Step 600
600
#725DCE
oklch(55.6% 0.168 288.2)
-
Step 700
700
#604CB2
oklch(49.1% 0.155 288.3)
-
Step 800
800
#4E3F90
oklch(42.7% 0.129 288.2)
-
Step 900
900
#403673
oklch(37.6% 0.101 288.1)
-
Step 950
950 (this color)
#1B1537
oklch(22.4% 0.064 288.3)
#1B1537 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) | #061B38 | 0.034 |
| Deuteranopia (no green cones) | #061936 | 0.033 |
| Tritanopia (no blue cones) | #131C23 | 0.053 |
| Achromatopsia (no color) | #1A1A1A | 0.064 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B1537
#1B1537
oklch(22.4% 0.064 288.3)
- #1E1D00
#1E1D00
oklch(22.5% 0.048 107.9)
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 #1B1537, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rich Black #0D1B2A ΔE 0.042
- Midnight Purple #280137 ΔE 0.054
- Dark #1B2431 ΔE 0.054
- Navy Blue #001146 ΔE 0.054
- Oxford Blue #1B263B ΔE 0.055
- Very Dark Purple #2A0134 ΔE 0.056
- Dark Indigo #1F0954 ΔE 0.060
- Dark Purple #35063E ΔE 0.065
Use #1B1537 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.