#1F51AB
Closest named color: Dusk Blue (#26538D). oklch(45.6% 0.154 261.1), rgb(31, 81, 171).
Aa
White text reads best on this color (7.43:1).
About this color
#1F51AB is a medium-dark, vivid blue. In OKLCH its lightness is 46%, its chroma 0.154 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Dusk Blue (#26538D), ΔE 0.050 away. White text reads best on it, at 7.43:1.
| Hue family | Blues |
| Lightness | medium-dark (46%) |
| Chroma | vivid (0.154) |
| Temperature | cool |
| Nearest name | Dusk Blue (#26538D) |
| Black text | 2.82:1 |
| White text | 7.43:1 |
Values
| HEX | #1F51AB |
| RGB | rgb(31, 81, 171) |
| HSL | hsl(219, 69%, 40%) |
| OKLCH | oklch(45.6% 0.154 261.1) |
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 #1F51AB | 7.43:1 | AAA | Lc -90.2 | Preferred for body text |
| Black text on #1F51AB | 2.82:1 | Fails | Lc 18.7 | Dividers and decoration only |
| #1F51AB text on white | 7.43:1 | AAA | Lc 85.3 | Fine for body text |
| #1F51AB text on black | 2.82:1 | Fails | Lc -16.7 | Dividers and decoration only |
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 800.
-
Step 50
50
#F1F6FE
oklch(97.2% 0.012 259.8)
-
Step 100
100
#E0EAFC
oklch(93.5% 0.027 262.3)
-
Step 200
200
#C7DAFB
oklch(88.5% 0.05 261.5)
-
Step 300
300
#A0C2FB
oklch(81% 0.089 260.6)
-
Step 400
400
#6C9FFA
oklch(70.7% 0.145 261.3)
-
Step 500
500
#4484F7
oklch(63.1% 0.184 261)
-
Step 600
600
#256AE6
oklch(55.6% 0.201 261.1)
-
Step 700
700
#1857C8
oklch(49% 0.187 261.2)
-
Step 800
800 (this color)
#1F51AB
oklch(45.6% 0.154 261.1)
-
Step 900
900
#193E80
oklch(37.8% 0.12 260.9)
-
Step 950
950
#0F254B
oklch(27% 0.076 260.5)
#1F51AB 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) | #105CAE | 0.029 |
| Deuteranopia (no green cones) | #004FA9 | 0.017 |
| Tritanopia (no blue cones) | #006776 | 0.119 |
| Achromatopsia (no color) | #555555 | 0.154 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1F51AB
#1F51AB
oklch(45.6% 0.154 261.1)
- #715000
#715000
oklch(45.5% 0.094 81.1)
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 #1F51AB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusk Blue #26538D ΔE 0.050
- Cobalt #1E488F ΔE 0.050
- Blue Blue #2242C7 ΔE 0.057
- Denim Blue #3B5B92 ΔE 0.060
- Sapphire #2138AB ΔE 0.061
- Blueberry #464196 ΔE 0.062
- Light Navy #155084 ΔE 0.065
- Light Navy Blue #2E5A88 ΔE 0.067
Use #1F51AB 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.