#178DEF
Closest named color: Dodger Blue (#1E90FF). oklch(63.4% 0.175 250.6), rgb(23, 141, 239).
Aa
Black text reads best on this color (6.09:1).
About this color
#178DEF is a medium-light, vivid blue. In OKLCH its lightness is 63%, its chroma 0.175 and its hue 251°. Its hue sits on the cool side of the wheel. The nearest named color is Dodger Blue (#1E90FF), ΔE 0.025 away. Black text reads best on it, at 6.09:1.
| Hue family | Blues |
| Lightness | medium-light (63%) |
| Chroma | vivid (0.175) |
| Temperature | cool |
| Nearest name | Dodger Blue (#1E90FF) |
| Black text | 6.09:1 |
| White text | 3.44:1 |
Values
| HEX | #178DEF |
| RGB | rgb(23, 141, 239) |
| HSL | hsl(207, 87%, 51%) |
| OKLCH | oklch(63.4% 0.175 250.6) |
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 #178DEF | 3.44:1 | AA large text | Lc -66.8 | Content text, not long reading |
| Black text on #178DEF | 6.09:1 | AA | Lc 42.7 | Non-text elements, placeholder text |
| #178DEF text on white | 3.44:1 | AA large text | Lc 61.4 | Content text, not long reading |
| #178DEF text on black | 6.09:1 | AA | Lc -40.3 | Non-text elements, placeholder text |
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 500.
-
Step 50
50
#F0F6FD
oklch(97.1% 0.011 252.1)
-
Step 100
100
#DEECFA
oklch(93.7% 0.024 248.1)
-
Step 200
200
#C2DCF8
oklch(88.4% 0.048 250.3)
-
Step 300
300
#97C5F6
oklch(80.9% 0.085 250.5)
-
Step 400
400
#59A5F2
oklch(70.7% 0.136 250.6)
-
Step 500
500 (this color)
#178DEF
oklch(63.4% 0.175 250.6)
-
Step 600
600
#0075CC
oklch(55.6% 0.16 250.6)
-
Step 700
700
#0062AD
oklch(49.1% 0.142 250.8)
-
Step 800
800
#00508F
oklch(42.6% 0.123 250.8)
-
Step 900
900
#004378
oklch(37.8% 0.108 250.3)
-
Step 950
950
#042748
oklch(26.9% 0.073 251.2)
#178DEF 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) | #5B94F3 | 0.051 |
| Deuteranopia (no green cones) | #3582ED | 0.029 |
| Tritanopia (no blue cones) | #00A5B2 | 0.128 |
| Achromatopsia (no color) | #8A8A8A | 0.175 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #178DEF
#178DEF
oklch(63.4% 0.175 250.6)
- #BE7900
#BE7900
oklch(63.4% 0.137 70.2)
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 #178DEF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dodger Blue #1E90FF ΔE 0.025
- Dark Sky Blue #448EE4 ΔE 0.028
- Chefchaouen Blue #4895EF ΔE 0.037
- Soft Blue #6488EA ΔE 0.053
- Water Blue #0E87CC ΔE 0.054
- Clear Blue #247AFD ΔE 0.055
- Cornflower Blue #6495ED ΔE 0.060
- Cornflower #6A79F7 ΔE 0.076
Use #178DEF 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.