#21718E
Closest named color: Sea Blue (#047495). oklch(51.5% 0.087 226.9), rgb(33, 113, 142).
Aa
White text reads best on this color (5.50:1).
About this color
#21718E is a medium-dark, moderately saturated teal or cyan. In OKLCH its lightness is 51%, its chroma 0.087 and its hue 227°. Its hue sits on the cool side of the wheel. The nearest named color is Sea Blue (#047495), ΔE 0.014 away. White text reads best on it, at 5.50:1.
| Hue family | Teals and cyans |
| Lightness | medium-dark (51%) |
| Chroma | moderately saturated (0.087) |
| Temperature | cool |
| Nearest name | Sea Blue (#047495) |
| Black text | 3.81:1 |
| White text | 5.50:1 |
Values
| HEX | #21718E |
| RGB | rgb(33, 113, 142) |
| HSL | hsl(196, 62%, 34%) |
| OKLCH | oklch(51.5% 0.087 226.9) |
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 #21718E | 5.50:1 | AA | Lc -82.5 | Fine for body text |
| Black text on #21718E | 3.81:1 | AA large text | Lc 26.9 | Dividers and decoration only |
| #21718E text on white | 5.50:1 | AA | Lc 77.1 | Fine for body text |
| #21718E text on black | 3.81:1 | AA large text | Lc -24.6 | Dividers and decoration only |
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 700.
-
Step 50
50
#F2F6F8
oklch(97.1% 0.005 228.8)
-
Step 100
100
#E2ECF0
oklch(93.7% 0.012 223.5)
-
Step 200
200
#CADDE5
oklch(88.6% 0.023 224.9)
-
Step 300
300
#A5C7D6
oklch(81% 0.042 226.4)
-
Step 400
400
#72AAC1
oklch(70.8% 0.067 225.7)
-
Step 500
500
#4A94B2
oklch(63.1% 0.086 227.1)
-
Step 600
600
#277E9E
oklch(55.7% 0.094 227.1)
-
Step 700
700 (this color)
#21718E
oklch(51.5% 0.087 226.9)
-
Step 800
800
#17576D
oklch(42.8% 0.072 225.6)
-
Step 900
900
#1B4759
oklch(37.6% 0.057 228.1)
-
Step 950
950
#112A34
oklch(27% 0.036 226.6)
#21718E 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) | #616F8F | 0.064 |
| Deuteranopia (no green cones) | #53648E | 0.057 |
| Tritanopia (no blue cones) | #00797B | 0.046 |
| Achromatopsia (no color) | #696969 | 0.087 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21718E
#21718E
oklch(51.5% 0.087 226.9)
- #90573A
#90573A
oklch(51.5% 0.087 47.1)
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 #21718E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sea Blue #047495 ΔE 0.014
- Ocean Blue #03719C ΔE 0.024
- Ocean #017B92 ΔE 0.029
- Muted Blue #3B719F ΔE 0.036
- Deep Aqua #08787F ΔE 0.038
- Peacock Blue #016795 ΔE 0.039
- Metallic Blue #4F738E ΔE 0.042
- Denim #3B638C ΔE 0.043
Use #21718E 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.