#51999B
Closest named color: Cadet Blue (#5F9EA0). oklch(63.7% 0.072 197.9), rgb(81, 153, 155).
Aa
Black text reads best on this color (6.37:1).
About this color
#51999B is a medium-light, moderately saturated teal or cyan. In OKLCH its lightness is 64%, its chroma 0.072 and its hue 198°. Its hue sits on the cool side of the wheel. The nearest named color is Cadet Blue (#5F9EA0), ΔE 0.022 away. Black text reads best on it, at 6.37:1.
| Hue family | Teals and cyans |
| Lightness | medium-light (64%) |
| Chroma | moderately saturated (0.072) |
| Temperature | cool |
| Nearest name | Cadet Blue (#5F9EA0) |
| Black text | 6.37:1 |
| White text | 3.29:1 |
Values
| HEX | #51999B |
| RGB | rgb(81, 153, 155) |
| HSL | hsl(182, 31%, 46%) |
| OKLCH | oklch(63.7% 0.072 197.9) |
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 #51999B | 3.29:1 | AA large text | Lc -65.6 | Content text, not long reading |
| Black text on #51999B | 6.37:1 | AA | Lc 43.9 | Non-text elements, placeholder text |
| #51999B text on white | 3.29:1 | AA large text | Lc 60.1 | Content text, not long reading |
| #51999B text on black | 6.37:1 | AA | Lc -41.6 | 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 500.
-
Step 50
50
#F2F6F6
oklch(97% 0.004 197.1)
-
Step 100
100
#E2ECEC
oklch(93.6% 0.011 197)
-
Step 200
200
#CBDDDE
oklch(88.4% 0.019 200.8)
-
Step 300
300
#A7C8C9
oklch(80.9% 0.035 198.7)
-
Step 400
400
#76ACAD
oklch(70.7% 0.057 197.4)
-
Step 500
500 (this color)
#51999B
oklch(63.7% 0.072 197.9)
-
Step 600
600
#2E8184
oklch(55.5% 0.078 198.5)
-
Step 700
700
#1F6D70
oklch(49% 0.073 198.8)
-
Step 800
800
#1D595B
oklch(42.7% 0.06 198.3)
-
Step 900
900
#1F494B
oklch(37.7% 0.047 199.5)
-
Step 950
950
#132B2C
oklch(27% 0.03 199.1)
#51999B 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) | #90939B | 0.074 |
| Deuteranopia (no green cones) | #848A9C | 0.070 |
| Tritanopia (no blue cones) | #279D99 | 0.029 |
| Achromatopsia (no color) | #8E8E8E | 0.073 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #51999B
#51999B
oklch(63.7% 0.072 197.9)
- #B37A7B
#B37A7B
oklch(63.8% 0.072 18.1)
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 #51999B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cadet Blue #5F9EA0 ΔE 0.022
- Sea #3C9992 ΔE 0.023
- Grey Teal #5E9B8A ΔE 0.030
- Dull Teal #5F9E8F ΔE 0.030
- Persian Green #2A9D8F ΔE 0.037
- Dusty Teal #4C9085 ΔE 0.038
- Blue Green #0F9B8E ΔE 0.044
- Teal Green #0A9396 ΔE 0.045
Use #51999B 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.