#21B4BC
Closest named color: Turquoise Blue (#06B1C4). oklch(70.3% 0.114 200.8), rgb(33, 180, 188).
Aa
Black text reads best on this color (8.31:1).
About this color
#21B4BC is a medium-light, moderately saturated teal or cyan. In OKLCH its lightness is 70%, its chroma 0.114 and its hue 201°. Its hue sits on the cool side of the wheel. The nearest named color is Turquoise Blue (#06B1C4), ΔE 0.018 away. Black text reads best on it, at 8.31:1.
| Hue family | Teals and cyans |
| Lightness | medium-light (70%) |
| Chroma | moderately saturated (0.114) |
| Temperature | cool |
| Nearest name | Turquoise Blue (#06B1C4) |
| Black text | 8.31:1 |
| White text | 2.52:1 |
Values
| HEX | #21B4BC |
| RGB | rgb(33, 180, 188) |
| HSL | hsl(183, 70%, 43%) |
| OKLCH | oklch(70.3% 0.114 200.8) |
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 #21B4BC | 2.52:1 | Fails | Lc -54.1 | Large or bold text, headings |
| Black text on #21B4BC | 8.31:1 | AAA | Lc 55.0 | Large or bold text, headings |
| #21B4BC text on white | 2.52:1 | Fails | Lc 49.0 | Large or bold text, headings |
| #21B4BC text on black | 8.31:1 | AAA | Lc -53.0 | Large or bold text, headings |
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 400.
-
Step 50
50
#EFF7F8
oklch(97% 0.009 205.9)
-
Step 100
100
#DBEEEF
oklch(93.5% 0.02 200.6)
-
Step 200
200
#BCE2E4
oklch(88.6% 0.04 200.4)
-
Step 300
300
#88CFD3
oklch(80.9% 0.071 200.4)
-
Step 400
400 (this color)
#21B4BC
oklch(70.3% 0.114 200.8)
-
Step 500
500
#009CA4
oklch(63% 0.107 201.2)
-
Step 600
600
#00838A
oklch(55.5% 0.094 201.4)
-
Step 700
700
#006E74
oklch(49% 0.083 201.4)
-
Step 800
800
#005B5F
oklch(42.8% 0.073 200)
-
Step 900
900
#004B4F
oklch(37.5% 0.064 200.9)
-
Step 950
950
#002D30
oklch(27% 0.046 201.8)
#21B4BC 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) | #A6ACBD | 0.116 |
| Deuteranopia (no green cones) | #919DBD | 0.106 |
| Tritanopia (no blue cones) | #00BBB6 | 0.025 |
| Achromatopsia (no color) | #A3A3A3 | 0.115 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21B4BC
#21B4BC
oklch(70.3% 0.114 200.8)
- #DD8181
#DD8181
oklch(70.2% 0.114 20.3)
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 #21B4BC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Turquoise Blue #06B1C4 ΔE 0.018
- Light Sea Green #20B2AA ΔE 0.026
- Topaz #13BBAF ΔE 0.032
- Greeny Blue #42B395 ΔE 0.056
- Cadet Blue #5F9EA0 ΔE 0.067
- Dark Turquoise #00CED1 ΔE 0.072
- Greyblue #77A1B5 ΔE 0.073
- Dull Teal #5F9E8F ΔE 0.077
Use #21B4BC 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.