Ultramarine #2000B1
Ultramarine is a dark, vivid blue with hex code #2000B1 and RGB rgb(32, 0, 177).
Aa
White text reads best on this color (12.38:1).
About this color
#2000B1 is a dark, vivid blue. In OKLCH its lightness is 35%, its chroma 0.231 and its hue 271°. Its hue sits on the cool side of the wheel. It is the named color Ultramarine. White text reads best on it, at 12.38:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | vivid (0.231) |
| Temperature | cool |
| Nearest name | Ultramarine |
| Black text | 1.69:1 |
| White text | 12.38:1 |
Colors that go with Ultramarine
Matches found by rotating Ultramarine around the OKLCH hue wheel, each labelled with the closest name in our list.
Complementary
The opposite hue (180°).
Analogous
Neighbouring hues, 30° either side.
Triadic
Three hues spaced 120° apart.
Color palettes with Ultramarine
Curated color palettes that contain a color within ΔE 0.06 (OKLab) of Ultramarine, closest first.
Similar named colors
The eight named colors closest to Ultramarine, with their ΔE distance.
- Cobalt Blue #030AA7 ΔE 0.031
- Indigo Blue #3A18B1 ΔE 0.051
- True Blue #010FCC ΔE 0.053
- Royal #0C1793 ΔE 0.053
- Medium Blue #0000CD ΔE 0.053
- Sapphire #2138AB ΔE 0.071
- Ultramarine Blue #1805DB ΔE 0.072
- Imperial Purple #480CA8 ΔE 0.077
More about Ultramarine
How to make Ultramarine
A starting recipe from common paint colors, found with a spectral paint model (the color mixer’s paint mode). Real pigments vary, so mix a small test batch and adjust.
- 1 part blue
- 1 part purple
Recipe result: #3B3A9F, a difference of ΔE 0.097 from Ultramarine. Ultramarine is more vivid than these paints can mix, so start from a ready-made blue paint and adjust it.
Codes for Ultramarine in every format
| HEX | #2000B1 |
| RGB | rgb(32, 0, 177) |
| HSL | hsl(251, 100%, 35%) |
| OKLCH | oklch(35.5% 0.231 270.6) |
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 #2000B1 | 12.38:1 | AAA | Lc -99.3 | Preferred for body text |
| Black text on #2000B1 | 1.69:1 | Fails | Lc 8.5 | Not readable |
| #2000B1 text on white | 12.38:1 | AAA | Lc 95.4 | Preferred for body text |
| #2000B1 text on black | 1.69:1 | Fails | Lc 0.0 | Not readable |
Shades and tints of Ultramarine
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 900.
-
Step 50
50
#F2F5FF
oklch(97.1% 0.014 272.7)
-
Step 100
100
#E2E9FF
oklch(93.5% 0.031 271.7)
-
Step 200
200
#CBD8FF
oklch(88.5% 0.056 270.7)
-
Step 300
300
#A9BEFF
oklch(80.9% 0.095 270.4)
-
Step 400
400
#7D99FF
oklch(70.7% 0.152 270.5)
-
Step 500
500
#5F7BFF
oklch(63.1% 0.198 270.7)
-
Step 600
600
#4558FF
oklch(55.6% 0.245 270.7)
-
Step 700
700
#362CFF
oklch(49.2% 0.287 270.7)
-
Step 800
800
#2C00E3
oklch(42.7% 0.278 270.6)
-
Step 900
900 (this color)
#2000B1
oklch(35.5% 0.231 270.6)
-
Step 950
950
#12136C
oklch(27% 0.146 270.6)
Ultramarine 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) | #003CB5 | 0.076 |
| Deuteranopia (no green cones) | #002CAE | 0.045 |
| Tritanopia (no blue cones) | #004766 | 0.173 |
| Achromatopsia (no color) | #343434 | 0.233 |
Use Ultramarine 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.