#21708F
Closest named color: Sea Blue (#047495). oklch(51.3% 0.088 228.9), rgb(33, 112, 143).
Aa
White text reads best on this color (5.55:1).
About this color
#21708F is a medium-dark, moderately saturated teal or cyan. In OKLCH its lightness is 51%, its chroma 0.088 and its hue 229°. 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 5.55:1.
| Hue family | Teals and cyans |
| Lightness | medium-dark (51%) |
| Chroma | moderately saturated (0.088) |
| Temperature | cool |
| Nearest name | Sea Blue (#047495) |
| Black text | 3.77:1 |
| White text | 5.55:1 |
Values
| HEX | #21708F |
| RGB | rgb(33, 112, 143) |
| HSL | hsl(197, 63%, 35%) |
| OKLCH | oklch(51.3% 0.088 228.9) |
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 #21708F | 5.55:1 | AA | Lc -82.7 | Fine for body text |
| Black text on #21708F | 3.77:1 | AA large text | Lc 26.6 | Dividers and decoration only |
| #21708F text on white | 5.55:1 | AA | Lc 77.4 | Fine for body text |
| #21708F text on black | 3.77:1 | AA large text | Lc -24.3 | 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
#CADDE6
oklch(88.6% 0.024 227.8)
-
Step 300
300
#A5C7D7
oklch(81% 0.043 228)
-
Step 400
400
#73A9C3
oklch(70.7% 0.068 229.7)
-
Step 500
500
#4A94B4
oklch(63.2% 0.088 228.7)
-
Step 600
600
#277D9F
oklch(55.5% 0.095 228.9)
-
Step 700
700 (this color)
#21708F
oklch(51.3% 0.088 228.9)
-
Step 800
800
#18566F
oklch(42.6% 0.073 229.5)
-
Step 900
900
#1C475A
oklch(37.7% 0.057 230)
-
Step 950
950
#122A34
oklch(27.1% 0.035 227.4)
#21708F 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) | #606E91 | 0.063 |
| Deuteranopia (no green cones) | #51648F | 0.053 |
| Tritanopia (no blue cones) | #00797A | 0.051 |
| Achromatopsia (no color) | #686868 | 0.088 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21708F
#21708F
oklch(51.3% 0.088 228.9)
- #8F5637
#8F5637
oklch(51.1% 0.088 48.5)
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 #21708F, 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 0.021
- Ocean #017B92 ΔE 0.032
- Muted Blue #3B719F ΔE 0.034
- Peacock Blue #016795 ΔE 0.035
- Denim #3B638C ΔE 0.040
- Deep Aqua #08787F ΔE 0.042
- Metallic Blue #4F738E ΔE 0.043
Use #21708F 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.