#128DD9
Closest named color: Water Blue (#0E87CC). oklch(62% 0.15 244.4), rgb(18, 141, 217).
Aa
Black text reads best on this color (5.83:1).
About this color
#128DD9 is a medium-light, vivid blue. In OKLCH its lightness is 62%, its chroma 0.150 and its hue 244°. Its hue sits on the cool side of the wheel. The nearest named color is Water Blue (#0E87CC), ΔE 0.024 away. Black text reads best on it, at 5.83:1.
| Hue family | Blues |
| Lightness | medium-light (62%) |
| Chroma | vivid (0.150) |
| Temperature | cool |
| Nearest name | Water Blue (#0E87CC) |
| Black text | 5.83:1 |
| White text | 3.59:1 |
Values
| HEX | #128DD9 |
| RGB | rgb(18, 141, 217) |
| HSL | hsl(203, 85%, 46%) |
| OKLCH | oklch(62% 0.15 244.4) |
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 #128DD9 | 3.59:1 | AA large text | Lc -68.5 | Content text, not long reading |
| Black text on #128DD9 | 5.83:1 | AA | Lc 41.1 | Non-text elements, placeholder text |
| #128DD9 text on white | 3.59:1 | AA large text | Lc 63.0 | Content text, not long reading |
| #128DD9 text on black | 5.83:1 | AA | Lc -38.7 | 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
#F0F6FC
oklch(97% 0.01 247.9)
-
Step 100
100
#DFECF7
oklch(93.7% 0.02 243.4)
-
Step 200
200
#C3DDF3
oklch(88.5% 0.041 243.7)
-
Step 300
300
#99C6ED
oklch(80.8% 0.073 245)
-
Step 400
400
#5BA8E4
oklch(70.7% 0.117 244.1)
-
Step 500
500 (this color)
#128DD9
oklch(62% 0.15 244.4)
-
Step 600
600
#0079BE
oklch(55.6% 0.139 244.6)
-
Step 700
700
#0066A0
oklch(49.2% 0.121 244)
-
Step 800
800
#005384
oklch(42.6% 0.106 244.3)
-
Step 900
900
#00456F
oklch(37.6% 0.093 244.3)
-
Step 950
950
#042942
oklch(27% 0.061 243.6)
#128DD9 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) | #6890DC | 0.062 |
| Deuteranopia (no green cones) | #4D7FD8 | 0.046 |
| Tritanopia (no blue cones) | #00A0A9 | 0.103 |
| Achromatopsia (no color) | #878787 | 0.150 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #128DD9
#128DD9
oklch(62% 0.15 244.4)
- #BF7100
#BF7100
oklch(62.1% 0.14 64.4)
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 #128DD9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Water Blue #0E87CC ΔE 0.024
- Dark Sky Blue #448EE4 ΔE 0.032
- Chefchaouen Blue #4895EF ΔE 0.050
- Cool Blue #4984B8 ΔE 0.055
- Dodger Blue #1E90FF ΔE 0.058
- Blue NCS #118AB2 ΔE 0.060
- Steel Blue #4682B4 ΔE 0.060
- Windows Blue #3778BF ΔE 0.063
Use #128DD9 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.