#51C5B3
Closest named color: Medium Aquamarine (#66CDAA). oklch(75.2% 0.108 181.4), rgb(81, 197, 179).
Aa
Black text reads best on this color (9.98:1).
About this color
#51C5B3 is a medium-light, moderately saturated teal or cyan. In OKLCH its lightness is 75%, its chroma 0.108 and its hue 181°. Its hue sits on the cool side of the wheel. The nearest named color is Medium Aquamarine (#66CDAA), ΔE 0.034 away. Black text reads best on it, at 9.98:1.
| Hue family | Teals and cyans |
| Lightness | medium-light (75%) |
| Chroma | moderately saturated (0.108) |
| Temperature | cool |
| Nearest name | Medium Aquamarine (#66CDAA) |
| Black text | 9.98:1 |
| White text | 2.10:1 |
Values
| HEX | #51C5B3 |
| RGB | rgb(81, 197, 179) |
| HSL | hsl(171, 50%, 55%) |
| OKLCH | oklch(75.2% 0.108 181.4) |
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 #51C5B3 | 2.10:1 | Fails | Lc -45.5 | Large or bold text, headings |
| Black text on #51C5B3 | 9.98:1 | AAA | Lc 63.0 | Content text, not long reading |
| #51C5B3 text on white | 2.10:1 | Fails | Lc 40.9 | Non-text elements, placeholder text |
| #51C5B3 text on black | 9.98:1 | AAA | Lc -61.4 | Content text, not long reading |
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
#EFF8F6
oklch(97.2% 0.01 181.4)
-
Step 100
100
#DDEEEB
oklch(93.6% 0.018 184.3)
-
Step 200
200
#BFE2DB
oklch(88.6% 0.038 182)
-
Step 300
300
#8FCFC3
oklch(80.8% 0.067 181.5)
-
Step 400
400 (this color)
#51C5B3
oklch(75.2% 0.108 181.4)
-
Step 500
500
#009F8E
oklch(63% 0.113 181.8)
-
Step 600
600
#008677
oklch(55.6% 0.1 181.4)
-
Step 700
700
#007164
oklch(49.2% 0.089 181.2)
-
Step 800
800
#005C52
oklch(42.6% 0.076 182.2)
-
Step 900
900
#004D44
oklch(37.7% 0.068 181.7)
-
Step 950
950
#002E28
oklch(27% 0.049 181.5)
#51C5B3 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) | #BDBAB2 | 0.115 |
| Deuteranopia (no green cones) | #ABADB5 | 0.109 |
| Tritanopia (no blue cones) | #00C8BF | 0.027 |
| Achromatopsia (no color) | #B3B3B3 | 0.109 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #51C5B3
#51C5B3
oklch(75.2% 0.108 181.4)
- #E791AA
#E791AA
oklch(75.2% 0.108 1.2)
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 #51C5B3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Medium Aquamarine #66CDAA ΔE 0.034
- Medium Turquoise #48D1CC ΔE 0.041
- Topaz #13BBAF ΔE 0.042
- Dark Turquoise #00CED1 ΔE 0.044
- Pale Teal #82CBB2 ΔE 0.047
- Seafoam Blue #78D1B6 ΔE 0.049
- Greeny Blue #42B395 ΔE 0.061
- Light Sea Green #20B2AA ΔE 0.063
Use #51C5B3 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.