#121F3F
Closest named color: Oxford Blue (#1B263B). oklch(24.7% 0.063 265.4), rgb(18, 31, 63).
Aa
White text reads best on this color (16.23:1).
About this color
#121F3F is a very dark, muted blue. In OKLCH its lightness is 25%, its chroma 0.063 and its hue 265°. Its hue sits on the cool side of the wheel. The nearest named color is Oxford Blue (#1B263B), ΔE 0.031 away. White text reads best on it, at 16.23:1.
| Hue family | Blues |
| Lightness | very dark (25%) |
| Chroma | muted (0.063) |
| Temperature | cool |
| Nearest name | Oxford Blue (#1B263B) |
| Black text | 1.29:1 |
| White text | 16.23:1 |
Values
| HEX | #121F3F |
| RGB | rgb(18, 31, 63) |
| HSL | hsl(223, 56%, 16%) |
| OKLCH | oklch(24.7% 0.063 265.4) |
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 #121F3F | 16.23:1 | AAA | Lc -105.6 | Preferred for body text |
| Black text on #121F3F | 1.29:1 | Fails | Lc 0.0 | Not readable |
| #121F3F text on white | 16.23:1 | AAA | Lc 103.1 | Preferred for body text |
| #121F3F text on black | 1.29:1 | 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
#F2F5FC
oklch(97% 0.01 267.4)
-
Step 100
100
#E3EAF9
oklch(93.6% 0.022 265.8)
-
Step 200
200
#CCD9F6
oklch(88.5% 0.042 266.3)
-
Step 300
300
#A9C0F2
oklch(80.8% 0.075 265.5)
-
Step 400
400
#7C9EEC
oklch(70.6% 0.121 265.5)
-
Step 500
500
#5C84E6
oklch(63.1% 0.154 265.5)
-
Step 600
600
#436BD4
oklch(55.5% 0.168 265.5)
-
Step 700
700
#3559B8
oklch(49.1% 0.156 265.4)
-
Step 800
800
#2C4994
oklch(42.6% 0.128 265.4)
-
Step 900
900
#273E76
oklch(37.7% 0.1 265.2)
-
Step 950
950 (this color)
#121F3F
oklch(24.7% 0.063 265.4)
#121F3F 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) | #102240 | 0.010 |
| Deuteranopia (no green cones) | #091E3E | 0.012 |
| Tritanopia (no blue cones) | #00262B | 0.054 |
| Achromatopsia (no color) | #202020 | 0.064 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #121F3F
#121F3F
oklch(24.7% 0.063 265.4)
- #2C1F00
#2C1F00
oklch(24.8% 0.051 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 #121F3F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Oxford Blue #1B263B ΔE 0.031
- Dark #1B2431 ΔE 0.038
- Rich Black #0D1B2A ΔE 0.042
- Navy Blue #001146 ΔE 0.054
- Jet #212529 ΔE 0.056
- Space Cadet #2B2D42 ΔE 0.064
- Dark Indigo #1F0954 ΔE 0.067
- Marine #042E60 ΔE 0.071
Use #121F3F 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.