#66788A
Closest named color: Grey Blue (#647D8E). oklch(56.5% 0.035 248.4), rgb(102, 120, 138).
Aa
Black text reads best on this color (4.61:1).
About this color
#66788A is a medium-dark, muted blue. In OKLCH its lightness is 56%, its chroma 0.035 and its hue 248°. Its hue sits on the cool side of the wheel. The nearest named color is Grey Blue (#647D8E), ΔE 0.014 away. Black text reads best on it, at 4.61:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | muted (0.035) |
| Temperature | cool |
| Nearest name | Grey Blue (#647D8E) |
| Black text | 4.61:1 |
| White text | 4.54:1 |
Values
| HEX | #66788A |
| RGB | rgb(102, 120, 138) |
| HSL | hsl(210, 15%, 47%) |
| OKLCH | oklch(56.5% 0.035 248.4) |
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 #66788A | 4.54:1 | AA | Lc -77.0 | Fine for body text |
| Black text on #66788A | 4.61:1 | AA | Lc 32.5 | Non-text elements, placeholder text |
| #66788A text on white | 4.54:1 | AA | Lc 71.6 | Content text, not long reading |
| #66788A text on black | 4.61:1 | AA | Lc -30.1 | 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 600.
-
Step 50
50
#F4F5F7
oklch(97% 0.003 264.5)
-
Step 100
100
#E7EAED
oklch(93.6% 0.005 247.9)
-
Step 200
200
#D5DADF
oklch(88.6% 0.009 247.9)
-
Step 300
300
#B9C2CB
oklch(81% 0.016 248)
-
Step 400
400
#95A2B0
oklch(70.6% 0.025 250.2)
-
Step 500
500
#7B8C9D
oklch(63.2% 0.032 248.3)
-
Step 600
600 (this color)
#66788A
oklch(56.5% 0.035 248.4)
-
Step 700
700
#526373
oklch(49.2% 0.033 246.9)
-
Step 800
800
#44515D
oklch(42.8% 0.026 246.3)
-
Step 900
900
#39434D
oklch(37.8% 0.022 248.4)
-
Step 950
950
#21272D
oklch(26.9% 0.014 248.4)
#66788A 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) | #71788B | 0.016 |
| Deuteranopia (no green cones) | #6D748A | 0.014 |
| Tritanopia (no blue cones) | #5C7C7E | 0.029 |
| Achromatopsia (no color) | #767676 | 0.035 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #66788A
#66788A
oklch(56.5% 0.035 248.4)
- #847260
#847260
oklch(56.4% 0.035 67)
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 #66788A, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Grey Blue #647D8E ΔE 0.014
- Battleship Grey #6B7C85 ΔE 0.018
- Battleship Gray #6C757D ΔE 0.020
- Slate Gray #708090 ΔE 0.028
- Steel Grey #6F828A ΔE 0.033
- Metallic Blue #4F738E ΔE 0.035
- Stormy Blue #507B9C ΔE 0.035
- Steel #738595 ΔE 0.043
Use #66788A 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.