#173DBA
Closest named color: Blue Blue (#2242C7). oklch(42.7% 0.2 265.1), rgb(23, 61, 186).
Aa
White text reads best on this color (8.70:1).
About this color
#173DBA is a dark, vivid blue. In OKLCH its lightness is 43%, its chroma 0.200 and its hue 265°. Its hue sits on the cool side of the wheel. The nearest named color is Blue Blue (#2242C7), ΔE 0.027 away. White text reads best on it, at 8.70:1.
| Hue family | Blues |
| Lightness | dark (43%) |
| Chroma | vivid (0.200) |
| Temperature | cool |
| Nearest name | Blue Blue (#2242C7) |
| Black text | 2.41:1 |
| White text | 8.70:1 |
Values
| HEX | #173DBA |
| RGB | rgb(23, 61, 186) |
| HSL | hsl(226, 78%, 41%) |
| OKLCH | oklch(42.7% 0.2 265.1) |
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 #173DBA | 8.70:1 | AAA | Lc -93.5 | Preferred for body text |
| Black text on #173DBA | 2.41:1 | Fails | Lc 15.1 | Dividers and decoration only |
| #173DBA text on white | 8.70:1 | AAA | Lc 88.9 | Fine for body text |
| #173DBA text on black | 2.41:1 | Fails | Lc -13.3 | 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 800.
-
Step 50
50
#F1F6FF
oklch(97.2% 0.013 262.4)
-
Step 100
100
#E0EAFF
oklch(93.6% 0.03 265.3)
-
Step 200
200
#C7D9FF
oklch(88.4% 0.056 265.2)
-
Step 300
300
#A3C0FF
oklch(80.9% 0.095 265.2)
-
Step 400
400
#729CFF
oklch(70.6% 0.153 265.4)
-
Step 500
500
#4D7FFF
oklch(63% 0.198 265.1)
-
Step 600
600
#2A5EFF
oklch(55.6% 0.245 265.1)
-
Step 700
700
#1B48E6
oklch(49.1% 0.241 265.1)
-
Step 800
800 (this color)
#173DBA
oklch(42.7% 0.2 265.1)
-
Step 900
900
#173793
oklch(37.8% 0.156 264.9)
-
Step 950
950
#0E2156
oklch(27% 0.099 265.2)
#173DBA 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) | #0053BE | 0.051 |
| Deuteranopia (no green cones) | #0044B8 | 0.016 |
| Tritanopia (no blue cones) | #005F76 | 0.152 |
| Achromatopsia (no color) | #4B4B4B | 0.201 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #173DBA
#173DBA
oklch(42.7% 0.2 265.1)
- #654A00
#654A00
oklch(42.7% 0.087 84.5)
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 #173DBA, closest first.
No curated palette has a color within ΔE 0.04 of #173DBA.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Blue Blue #2242C7 ΔE 0.027
- Sapphire #2138AB ΔE 0.027
- Majorelle Blue #3F37C9 ΔE 0.048
- Indigo Blue #3A18B1 ΔE 0.068
- True Blue #010FCC ΔE 0.071
- Cobalt #1E488F ΔE 0.076
- Blue With A Hint Of Purple #533CC6 ΔE 0.076
- Ultramarine Blue #1805DB ΔE 0.076
Use #173DBA 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.