#128DCB
Closest named color: Water Blue (#0E87CC). oklch(61.3% 0.134 239.1), rgb(18, 141, 203).
Aa
Black text reads best on this color (5.69:1).
About this color
#128DCB is a medium-dark, moderately saturated blue. In OKLCH its lightness is 61%, its chroma 0.134 and its hue 239°. Its hue sits on the cool side of the wheel. The nearest named color is Water Blue (#0E87CC), ΔE 0.018 away. Black text reads best on it, at 5.69:1.
| Hue family | Blues |
| Lightness | medium-dark (61%) |
| Chroma | moderately saturated (0.134) |
| Temperature | cool |
| Nearest name | Water Blue (#0E87CC) |
| Black text | 5.69:1 |
| White text | 3.68:1 |
Values
| HEX | #128DCB |
| RGB | rgb(18, 141, 203) |
| HSL | hsl(200, 84%, 43%) |
| OKLCH | oklch(61.3% 0.134 239.1) |
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 #128DCB | 3.68:1 | AA large text | Lc -69.4 | Content text, not long reading |
| Black text on #128DCB | 5.69:1 | AA | Lc 40.2 | Non-text elements, placeholder text |
| #128DCB text on white | 3.68:1 | AA large text | Lc 63.9 | Content text, not long reading |
| #128DCB text on black | 5.69:1 | AA | Lc -37.8 | 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
#F0F6FB
oklch(97% 0.009 242.8)
-
Step 100
100
#DFECF5
oklch(93.6% 0.018 237.8)
-
Step 200
200
#C4DDEF
oklch(88.5% 0.036 239.2)
-
Step 300
300
#9AC7E7
oklch(80.9% 0.066 239.6)
-
Step 400
400
#5DA9DB
oklch(70.6% 0.105 239.4)
-
Step 500
500 (this color)
#128DCB
oklch(61.3% 0.134 239.1)
-
Step 600
600
#007BB4
oklch(55.5% 0.126 239.3)
-
Step 700
700
#006898
oklch(49.2% 0.11 238.7)
-
Step 800
800
#00557E
oklch(42.8% 0.097 239.2)
-
Step 900
900
#004769
oklch(37.8% 0.084 238.3)
-
Step 950
950
#052A3E
oklch(27.1% 0.055 237.7)
#128DCB 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) | #6F8ECE | 0.070 |
| Deuteranopia (no green cones) | #577ECA | 0.055 |
| Tritanopia (no blue cones) | #009DA3 | 0.088 |
| Achromatopsia (no color) | #858585 | 0.134 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #128DCB
#128DCB
oklch(61.3% 0.134 239.1)
- #BE6D1D
#BE6D1D
oklch(61.3% 0.134 59)
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 #128DCB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Water Blue #0E87CC ΔE 0.018
- Blue NCS #118AB2 ΔE 0.038
- Cool Blue #4984B8 ΔE 0.040
- Steel Blue #4682B4 ΔE 0.045
- Dark Sky Blue #448EE4 ΔE 0.048
- Off Blue #5684AE ΔE 0.056
- Windows Blue #3778BF ΔE 0.057
- Dusty Blue #5A86AD ΔE 0.059
Use #128DCB 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.