#218BE4
Closest named color: Dark Sky Blue (#448EE4). oklch(62.4% 0.162 249.7), rgb(33, 139, 228).
Aa
Black text reads best on this color (5.87:1).
About this color
#218BE4 is a medium-light, vivid blue. In OKLCH its lightness is 62%, its chroma 0.162 and its hue 250°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Sky Blue (#448EE4), ΔE 0.024 away. Black text reads best on it, at 5.87:1.
| Hue family | Blues |
| Lightness | medium-light (62%) |
| Chroma | vivid (0.162) |
| Temperature | cool |
| Nearest name | Dark Sky Blue (#448EE4) |
| Black text | 5.87:1 |
| White text | 3.57:1 |
Values
| HEX | #218BE4 |
| RGB | rgb(33, 139, 228) |
| HSL | hsl(207, 78%, 51%) |
| OKLCH | oklch(62.4% 0.162 249.7) |
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 #218BE4 | 3.57:1 | AA large text | Lc -68.3 | Content text, not long reading |
| Black text on #218BE4 | 5.87:1 | AA | Lc 41.3 | Non-text elements, placeholder text |
| #218BE4 text on white | 3.57:1 | AA large text | Lc 62.8 | Content text, not long reading |
| #218BE4 text on black | 5.87:1 | AA | Lc -38.9 | 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
#DFEBF9
oklch(93.5% 0.023 252.2)
-
Step 200
200
#C4DCF6
oklch(88.5% 0.044 250.4)
-
Step 300
300
#9AC5F2
oklch(80.9% 0.079 250)
-
Step 400
400
#5EA6EC
oklch(70.8% 0.126 249.4)
-
Step 500
500 (this color)
#218BE4
oklch(62.4% 0.162 249.7)
-
Step 600
600
#0076CA
oklch(55.7% 0.156 249.7)
-
Step 700
700
#0063AB
oklch(49.2% 0.138 249.7)
-
Step 800
800
#00518D
oklch(42.7% 0.12 249.5)
-
Step 900
900
#004377
oklch(37.7% 0.106 249.9)
-
Step 950
950
#062845
oklch(27% 0.066 248.8)
#218BE4 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) | #5F91E8 | 0.051 |
| Deuteranopia (no green cones) | #4080E2 | 0.031 |
| Tritanopia (no blue cones) | #00A0AC | 0.117 |
| Achromatopsia (no color) | #878787 | 0.162 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #218BE4
#218BE4
oklch(62.4% 0.162 249.7)
- #BB7600
#BB7600
oklch(62.5% 0.136 69.5)
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 #218BE4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Sky Blue #448EE4 ΔE 0.024
- Water Blue #0E87CC ΔE 0.038
- Dodger Blue #1E90FF ΔE 0.041
- Chefchaouen Blue #4895EF ΔE 0.042
- Soft Blue #6488EA ΔE 0.053
- Clear Blue #247AFD ΔE 0.061
- Cornflower Blue #6495ED ΔE 0.062
- Cool Blue #4984B8 ΔE 0.067
Use #218BE4 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.