#121FB6
Closest named color: Ultramarine (#2000B1). oklch(37.8% 0.225 266.5), rgb(18, 31, 182).
Aa
White text reads best on this color (11.06:1).
About this color
#121FB6 is a dark, vivid blue. In OKLCH its lightness is 38%, its chroma 0.225 and its hue 267°. Its hue sits on the cool side of the wheel. The nearest named color is Ultramarine (#2000B1), ΔE 0.029 away. White text reads best on it, at 11.06:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | vivid (0.225) |
| Temperature | cool |
| Nearest name | Ultramarine (#2000B1) |
| Black text | 1.89:1 |
| White text | 11.06:1 |
Values
| HEX | #121FB6 |
| RGB | rgb(18, 31, 182) |
| HSL | hsl(235, 82%, 39%) |
| OKLCH | oklch(37.8% 0.225 266.5) |
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 #121FB6 | 11.06:1 | AAA | Lc -97.9 | Preferred for body text |
| Black text on #121FB6 | 1.89:1 | Fails | Lc 10.0 | Not readable |
| #121FB6 text on white | 11.06:1 | AAA | Lc 93.9 | Preferred for body text |
| #121FB6 text on black | 1.89:1 | Fails | Lc -8.7 | 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 900.
-
Step 50
50
#F1F5FF
oklch(97% 0.014 268.5)
-
Step 100
100
#E0EAFF
oklch(93.6% 0.03 265.3)
-
Step 200
200
#C8D9FF
oklch(88.5% 0.056 266.2)
-
Step 300
300
#A4BFFF
oklch(80.8% 0.096 266.6)
-
Step 400
400
#759BFF
oklch(70.6% 0.153 266.8)
-
Step 500
500
#527EFF
oklch(63% 0.198 266.5)
-
Step 600
600
#335DFF
oklch(55.7% 0.244 266.6)
-
Step 700
700
#1F34FF
oklch(49.1% 0.287 266.6)
-
Step 800
800
#1900E9
oklch(42.7% 0.289 266.6)
-
Step 900
900 (this color)
#121FB6
oklch(37.8% 0.225 266.5)
-
Step 950
950
#08176A
oklch(26.9% 0.142 266.4)
#121FB6 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) | #0044BA | 0.068 |
| Deuteranopia (no green cones) | #0033B4 | 0.031 |
| Tritanopia (no blue cones) | #00516D | 0.169 |
| Achromatopsia (no color) | #3C3C3C | 0.226 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #121FB6
#121FB6
oklch(37.8% 0.225 266.5)
- #543E00
#543E00
oklch(37.8% 0.077 85.9)
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 #121FB6, closest first.
No curated palette has a color within ΔE 0.04 of #121FB6.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Ultramarine #2000B1 ΔE 0.029
- True Blue #010FCC ΔE 0.038
- Cobalt Blue #030AA7 ΔE 0.042
- Medium Blue #0000CD ΔE 0.043
- Sapphire #2138AB ΔE 0.050
- Indigo Blue #3A18B1 ΔE 0.052
- Ultramarine Blue #1805DB ΔE 0.059
- Royal #0C1793 ΔE 0.064
Use #121FB6 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.