#172DD1
Closest named color: Ultramarine Blue (#1805DB). oklch(42.8% 0.243 266.3), rgb(23, 45, 209).
Aa
White text reads best on this color (9.00:1).
About this color
#172DD1 is a dark, vivid blue. In OKLCH its lightness is 43%, its chroma 0.243 and its hue 266°. Its hue sits on the cool side of the wheel. The nearest named color is Ultramarine Blue (#1805DB), ΔE 0.036 away. White text reads best on it, at 9.00:1.
| Hue family | Blues |
| Lightness | dark (43%) |
| Chroma | vivid (0.243) |
| Temperature | cool |
| Nearest name | Ultramarine Blue (#1805DB) |
| Black text | 2.33:1 |
| White text | 9.00:1 |
Values
| HEX | #172DD1 |
| RGB | rgb(23, 45, 209) |
| HSL | hsl(233, 80%, 45%) |
| OKLCH | oklch(42.8% 0.243 266.3) |
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 #172DD1 | 9.00:1 | AAA | Lc -93.7 | Preferred for body text |
| Black text on #172DD1 | 2.33:1 | Fails | Lc 14.9 | Not readable |
| #172DD1 text on white | 9.00:1 | AAA | Lc 89.1 | Fine for body text |
| #172DD1 text on black | 2.33:1 | Fails | Lc -13.1 | 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
#F1F5FF
oklch(97% 0.014 268.5)
-
Step 100
100
#E0EAFF
oklch(93.6% 0.03 265.3)
-
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
#749CFF
oklch(70.8% 0.152 266)
-
Step 500
500
#527EFF
oklch(63% 0.198 266.5)
-
Step 600
600
#325DFF
oklch(55.6% 0.244 266.4)
-
Step 700
700
#1D34FF
oklch(49.1% 0.287 266.3)
-
Step 800
800 (this color)
#172DD1
oklch(42.8% 0.243 266.3)
-
Step 900
900
#152EA4
oklch(37.8% 0.189 266.4)
-
Step 950
950
#0C1D60
oklch(27.1% 0.12 266.6)
#172DD1 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) | #0052D6 | 0.071 |
| Deuteranopia (no green cones) | #003FCE | 0.030 |
| Tritanopia (no blue cones) | #00607F | 0.183 |
| Achromatopsia (no color) | #494949 | 0.244 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #172DD1
#172DD1
oklch(42.8% 0.243 266.3)
- #644B00
#644B00
oklch(42.8% 0.087 86.6)
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 #172DD1, closest first.
No curated palette has a color within ΔE 0.04 of #172DD1.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Ultramarine Blue #1805DB ΔE 0.036
- Blue Blue #2242C7 ΔE 0.043
- True Blue #010FCC ΔE 0.043
- Pure Blue #0203E2 ΔE 0.045
- Medium Blue #0000CD ΔE 0.051
- Majorelle Blue #3F37C9 ΔE 0.053
- Strong Blue #0C06F7 ΔE 0.063
- Sapphire #2138AB ΔE 0.063
Use #172DD1 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.