#178EE5
Closest named color: Dark Sky Blue (#448EE4). oklch(63% 0.162 247.8), rgb(23, 142, 229).
Aa
Black text reads best on this color (6.03:1).
About this color
#178EE5 is a medium-light, vivid blue. In OKLCH its lightness is 63%, its chroma 0.162 and its hue 248°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Sky Blue (#448EE4), ΔE 0.023 away. Black text reads best on it, at 6.03:1.
| Hue family | Blues |
| Lightness | medium-light (63%) |
| Chroma | vivid (0.162) |
| Temperature | cool |
| Nearest name | Dark Sky Blue (#448EE4) |
| Black text | 6.03:1 |
| White text | 3.47:1 |
Values
| HEX | #178EE5 |
| RGB | rgb(23, 142, 229) |
| HSL | hsl(205, 82%, 49%) |
| OKLCH | oklch(63% 0.162 247.8) |
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 #178EE5 | 3.47:1 | AA large text | Lc -67.2 | Content text, not long reading |
| Black text on #178EE5 | 6.03:1 | AA | Lc 42.3 | Non-text elements, placeholder text |
| #178EE5 text on white | 3.47:1 | AA large text | Lc 61.7 | Content text, not long reading |
| #178EE5 text on black | 6.03:1 | AA | Lc -39.9 | 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
#F0F6FC
oklch(97% 0.01 247.9)
-
Step 100
100
#DEECF9
oklch(93.6% 0.023 246)
-
Step 200
200
#C3DCF5
oklch(88.4% 0.044 248.3)
-
Step 300
300
#98C6F2
oklch(81% 0.079 247.7)
-
Step 400
400
#5AA6EB
oklch(70.6% 0.127 248)
-
Step 500
500 (this color)
#178EE5
oklch(63% 0.162 247.8)
-
Step 600
600
#0077C5
oklch(55.6% 0.149 247.9)
-
Step 700
700
#0064A7
oklch(49.1% 0.132 247.9)
-
Step 800
800
#00528A
oklch(42.8% 0.115 247.8)
-
Step 900
900
#004474
oklch(37.7% 0.101 247.8)
-
Step 950
950
#042845
oklch(27% 0.067 247.8)
#178EE5 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) | #6393E9 | 0.056 |
| Deuteranopia (no green cones) | #4482E3 | 0.036 |
| Tritanopia (no blue cones) | #00A3AE | 0.116 |
| Achromatopsia (no color) | #898989 | 0.162 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #178EE5
#178EE5
oklch(63% 0.162 247.8)
- #BF7600
#BF7600
oklch(63% 0.138 67.7)
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 #178EE5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Sky Blue #448EE4 ΔE 0.023
- Chefchaouen Blue #4895EF ΔE 0.038
- Dodger Blue #1E90FF ΔE 0.039
- Water Blue #0E87CC ΔE 0.041
- Soft Blue #6488EA ΔE 0.055
- Cornflower Blue #6495ED ΔE 0.060
- Clear Blue #247AFD ΔE 0.067
- Cool Blue #4984B8 ΔE 0.070
Use #178EE5 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.