#217BD8
Closest named color: Windows Blue (#3778BF). oklch(58.1% 0.164 253.5), rgb(33, 123, 216).
Aa
Black text reads best on this color (4.88:1).
About this color
#217BD8 is a medium-dark, vivid blue. In OKLCH its lightness is 58%, its chroma 0.164 and its hue 253°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.039 away. Black text reads best on it, at 4.88:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | vivid (0.164) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.88:1 |
| White text | 4.29:1 |
Values
| HEX | #217BD8 |
| RGB | rgb(33, 123, 216) |
| HSL | hsl(210, 73%, 49%) |
| OKLCH | oklch(58.1% 0.164 253.5) |
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 #217BD8 | 4.29:1 | AA large text | Lc -74.7 | Content text, not long reading |
| Black text on #217BD8 | 4.88:1 | AA | Lc 34.9 | Non-text elements, placeholder text |
| #217BD8 text on white | 4.29:1 | AA large text | Lc 69.2 | Content text, not long reading |
| #217BD8 text on black | 4.88:1 | AA | Lc -32.5 | 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 600.
-
Step 50
50
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E0EBF8
oklch(93.6% 0.021 252.5)
-
Step 200
200
#C7DBF4
oklch(88.4% 0.041 254)
-
Step 300
300
#A0C4F0
oklch(81% 0.074 253.7)
-
Step 400
400
#6AA4E8
oklch(70.7% 0.117 253.3)
-
Step 500
500
#3E8BE2
oklch(63.1% 0.152 253.6)
-
Step 600
600 (this color)
#217BD8
oklch(58.1% 0.164 253.5)
-
Step 700
700
#0260B4
oklch(49.1% 0.153 253.5)
-
Step 800
800
#0B4F91
oklch(42.7% 0.125 253.3)
-
Step 900
900
#144274
oklch(37.7% 0.099 253.5)
-
Step 950
950
#0E2744
oklch(27% 0.062 253.9)
#217BD8 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) | #4B83DC | 0.040 |
| Deuteranopia (no green cones) | #2673D6 | 0.021 |
| Tritanopia (no blue cones) | #00919F | 0.121 |
| Achromatopsia (no color) | #7A7A7A | 0.164 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #217BD8
#217BD8
oklch(58.1% 0.164 253.5)
- #A66D00
#A66D00
oklch(58.1% 0.124 73.2)
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 #217BD8, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.039
- Water Blue #0E87CC ΔE 0.041
- Royal Blue #4169E1 ΔE 0.051
- Cerulean Blue #056EEE ΔE 0.051
- Clear Blue #247AFD ΔE 0.057
- Dark Sky Blue #448EE4 ΔE 0.061
- Nice Blue #107AB0 ΔE 0.063
- Cool Blue #4984B8 ΔE 0.066
Use #217BD8 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.