#128BC5
Closest named color: Water Blue (#0E87CC). oklch(60.5% 0.129 237.7), rgb(18, 139, 197).
Aa
Black text reads best on this color (5.52:1).
About this color
#128BC5 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 60%, its chroma 0.129 and its hue 238°. 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 5.52:1.
| Hue family | Blues |
| Lightness | medium-dark (60%) |
| Chroma | moderately saturated (0.129) |
| Temperature | cool |
| Nearest name | Water Blue (#0E87CC) |
| Black text | 5.52:1 |
| White text | 3.80:1 |
Values
| HEX | #128BC5 |
| RGB | rgb(18, 139, 197) |
| HSL | hsl(199, 83%, 42%) |
| OKLCH | oklch(60.5% 0.129 237.7) |
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 #128BC5 | 3.80:1 | AA large text | Lc -70.5 | Content text, not long reading |
| Black text on #128BC5 | 5.52:1 | AA | Lc 39.1 | Non-text elements, placeholder text |
| #128BC5 text on white | 3.80:1 | AA large text | Lc 65.0 | Content text, not long reading |
| #128BC5 text on black | 5.52:1 | AA | Lc -36.7 | 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
#C4DDEE
oklch(88.4% 0.036 237.6)
-
Step 300
300
#9BC7E5
oklch(80.9% 0.063 238.4)
-
Step 400
400
#5FAAD8
oklch(70.8% 0.101 237.4)
-
Step 500
500 (this color)
#128BC5
oklch(60.5% 0.129 237.7)
-
Step 600
600
#007CB2
oklch(55.6% 0.123 237.7)
-
Step 700
700
#006896
oklch(49.1% 0.108 237.6)
-
Step 800
800
#00557C
oklch(42.7% 0.094 237.9)
-
Step 900
900
#004768
oklch(37.7% 0.083 237.5)
-
Step 950
950
#062A3D
oklch(27.1% 0.053 236.9)
#128BC5 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) | #6F8BC8 | 0.071 |
| Deuteranopia (no green cones) | #587CC4 | 0.057 |
| Tritanopia (no blue cones) | #009A9F | 0.083 |
| Achromatopsia (no color) | #838383 | 0.129 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #128BC5
#128BC5
oklch(60.5% 0.129 237.7)
- #BA6B24
#BA6B24
oklch(60.5% 0.129 57.6)
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 #128BC5, 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 0.029
- Cool Blue #4984B8 ΔE 0.035
- Steel Blue #4682B4 ΔE 0.038
- Off Blue #5684AE ΔE 0.051
- Windows Blue #3778BF ΔE 0.052
- Nice Blue #107AB0 ΔE 0.054
- Dusty Blue #5A86AD ΔE 0.054
Use #128BC5 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.