#1F3991
Closest named color: Cobalt (#1E488F). oklch(38.4% 0.149 266.6), rgb(31, 57, 145).
Aa
White text reads best on this color (10.23:1).
About this color
#1F3991 is a dark, vivid blue. In OKLCH its lightness is 38%, its chroma 0.149 and its hue 267°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.040 away. White text reads best on it, at 10.23:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | vivid (0.149) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.05:1 |
| White text | 10.23:1 |
Values
| HEX | #1F3991 |
| RGB | rgb(31, 57, 145) |
| HSL | hsl(226, 65%, 35%) |
| OKLCH | oklch(38.4% 0.149 266.6) |
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 #1F3991 | 10.23:1 | AAA | Lc -97.3 | Preferred for body text |
| Black text on #1F3991 | 2.05:1 | Fails | Lc 10.7 | Not readable |
| #1F3991 text on white | 10.23:1 | AAA | Lc 93.2 | Preferred for body text |
| #1F3991 text on black | 2.05:1 | Fails | Lc -9.3 | 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
#E1EAFF
oklch(93.7% 0.03 267.2)
-
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
#2649E0
oklch(49% 0.231 266.5)
-
Step 800
800
#203EB5
oklch(42.7% 0.191 266.6)
-
Step 900
900 (this color)
#1F3991
oklch(38.4% 0.149 266.6)
-
Step 950
950
#112154
oklch(27% 0.095 266.7)
#1F3991 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) | #004694 | 0.035 |
| Deuteranopia (no green cones) | #003C8F | 0.020 |
| Tritanopia (no blue cones) | #004F5F | 0.116 |
| Achromatopsia (no color) | #414141 | 0.149 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1F3991
#1F3991
oklch(38.4% 0.149 266.6)
- #564000
#564000
oklch(38.5% 0.079 86.5)
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 #1F3991, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.040
- Sapphire #2138AB ΔE 0.043
- Twilight Blue #0A437A ΔE 0.051
- Blueberry #464196 ΔE 0.060
- Dark Slate Blue #483D8B ΔE 0.060
- Light Navy #155084 ΔE 0.069
- Marine Blue #01386A ΔE 0.071
- Dusk Blue #26538D ΔE 0.074
Use #1F3991 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.