#1F3A78
Closest named color: Twilight Blue (#0A437A). oklch(36.5% 0.111 264), rgb(31, 58, 120).
Aa
White text reads best on this color (10.85:1).
About this color
#1F3A78 is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.111 and its hue 264°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.027 away. White text reads best on it, at 10.85:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.111) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.93:1 |
| White text | 10.85:1 |
Values
| HEX | #1F3A78 |
| RGB | rgb(31, 58, 120) |
| HSL | hsl(222, 59%, 30%) |
| OKLCH | oklch(36.5% 0.111 264) |
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 #1F3A78 | 10.85:1 | AAA | Lc -98.7 | Preferred for body text |
| Black text on #1F3A78 | 1.93:1 | Fails | Lc 9.1 | Not readable |
| #1F3A78 text on white | 10.85:1 | AAA | Lc 94.8 | Preferred for body text |
| #1F3A78 text on black | 1.93:1 | Fails | Lc -7.8 | 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
#F2F6FD
oklch(97.2% 0.01 261.8)
-
Step 100
100
#E2EAFB
oklch(93.6% 0.025 265.6)
-
Step 200
200
#CADAF9
oklch(88.6% 0.046 263.7)
-
Step 300
300
#A5C1F7
oklch(80.9% 0.083 263.3)
-
Step 400
400
#769EF4
oklch(70.7% 0.134 264.3)
-
Step 500
500
#5383EF
oklch(63% 0.17 264.1)
-
Step 600
600
#396ADE
oklch(55.6% 0.185 264)
-
Step 700
700
#2C57C1
oklch(49% 0.173 264.3)
-
Step 800
800
#25489C
oklch(42.7% 0.143 264.2)
-
Step 900
900 (this color)
#1F3A78
oklch(36.5% 0.111 264)
-
Step 950
950
#142448
oklch(26.8% 0.07 264.2)
#1F3A78 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) | #16417A | 0.020 |
| Deuteranopia (no green cones) | #003977 | 0.022 |
| Tritanopia (no blue cones) | #004953 | 0.090 |
| Achromatopsia (no color) | #3D3D3D | 0.111 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1F3A78
#1F3A78
oklch(36.5% 0.111 264)
- #513A00
#513A00
oklch(36.5% 0.075 83.5)
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 #1F3A78, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.027
- Marine Blue #01386A ΔE 0.035
- Cobalt #1E488F ΔE 0.052
- Prussian Blue #1D3557 ΔE 0.058
- Marine #042E60 ΔE 0.061
- Light Navy #155084 ΔE 0.064
- Dark Slate Blue #483D8B ΔE 0.068
- Dark Grey Blue #29465B ΔE 0.070
Use #1F3A78 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.