#128DD1
Closest named color: Water Blue (#0E87CC). oklch(61.6% 0.141 241.5), rgb(18, 141, 209).
Aa
Black text reads best on this color (5.75:1).
About this color
#128DD1 is a medium-dark, vivid blue. In OKLCH its lightness is 62%, its chroma 0.141 and its hue 242°. 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 5.75:1.
| Hue family | Blues |
| Lightness | medium-dark (62%) |
| Chroma | vivid (0.141) |
| Temperature | cool |
| Nearest name | Water Blue (#0E87CC) |
| Black text | 5.75:1 |
| White text | 3.64:1 |
Values
| HEX | #128DD1 |
| RGB | rgb(18, 141, 209) |
| HSL | hsl(201, 84%, 45%) |
| OKLCH | oklch(61.6% 0.141 241.5) |
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 #128DD1 | 3.64:1 | AA large text | Lc -69.0 | Content text, not long reading |
| Black text on #128DD1 | 5.75:1 | AA | Lc 40.6 | Non-text elements, placeholder text |
| #128DD1 text on white | 3.64:1 | AA large text | Lc 63.5 | Content text, not long reading |
| #128DD1 text on black | 5.75:1 | AA | Lc -38.2 | 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
#DFECF6
oklch(93.6% 0.019 240.7)
-
Step 200
200
#C4DDF1
oklch(88.5% 0.038 242.2)
-
Step 300
300
#99C7EA
oklch(80.9% 0.069 241.5)
-
Step 400
400
#5CA9DF
oklch(70.7% 0.11 241.2)
-
Step 500
500 (this color)
#128DD1
oklch(61.6% 0.141 241.5)
-
Step 600
600
#007AB8
oklch(55.5% 0.131 241.7)
-
Step 700
700
#00679C
oklch(49.2% 0.116 241.5)
-
Step 800
800
#005481
oklch(42.7% 0.101 241.9)
-
Step 900
900
#00466C
oklch(37.7% 0.089 241.5)
-
Step 950
950
#052940
oklch(26.9% 0.058 242)
#128DD1 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) | #6C8FD4 | 0.067 |
| Deuteranopia (no green cones) | #537FD0 | 0.050 |
| Tritanopia (no blue cones) | #009EA5 | 0.095 |
| Achromatopsia (no color) | #868686 | 0.141 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #128DD1
#128DD1
oklch(61.6% 0.141 241.5)
- #C06E07
#C06E07
oklch(61.7% 0.141 61.5)
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 #128DD1, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Water Blue #0E87CC ΔE 0.018
- Dark Sky Blue #448EE4 ΔE 0.041
- Cool Blue #4984B8 ΔE 0.046
- Blue NCS #118AB2 ΔE 0.047
- Steel Blue #4682B4 ΔE 0.051
- Windows Blue #3778BF ΔE 0.059
- Chefchaouen Blue #4895EF ΔE 0.059
- Off Blue #5684AE ΔE 0.062
Use #128DD1 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.