#138BD4
Closest named color: Water Blue (#0E87CC). oklch(61.3% 0.145 243.8), rgb(19, 139, 212).
Aa
Black text reads best on this color (5.67:1).
About this color
#138BD4 is a medium-dark, vivid blue. In OKLCH its lightness is 61%, its chroma 0.145 and its hue 244°. Its hue sits on the cool side of the wheel. The nearest named color is Water Blue (#0E87CC), ΔE 0.015 away. Black text reads best on it, at 5.67:1.
| Hue family | Blues |
| Lightness | medium-dark (61%) |
| Chroma | vivid (0.145) |
| Temperature | cool |
| Nearest name | Water Blue (#0E87CC) |
| Black text | 5.67:1 |
| White text | 3.70:1 |
Values
| HEX | #138BD4 |
| RGB | rgb(19, 139, 212) |
| HSL | hsl(203, 84%, 45%) |
| OKLCH | oklch(61.3% 0.145 243.8) |
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 #138BD4 | 3.70:1 | AA large text | Lc -69.5 | Content text, not long reading |
| Black text on #138BD4 | 5.67:1 | AA | Lc 40.0 | Non-text elements, placeholder text |
| #138BD4 text on white | 3.70:1 | AA large text | Lc 64.0 | Content text, not long reading |
| #138BD4 text on black | 5.67:1 | AA | Lc -37.6 | 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
#C4DDF2
oklch(88.6% 0.039 243.5)
-
Step 300
300
#99C6EC
oklch(80.8% 0.072 244.3)
-
Step 400
400
#5DA8E2
oklch(70.7% 0.114 243.7)
-
Step 500
500 (this color)
#138BD4
oklch(61.3% 0.145 243.8)
-
Step 600
600
#0079BC
oklch(55.5% 0.136 243.9)
-
Step 700
700
#00669F
oklch(49.1% 0.12 243.6)
-
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
#052941
oklch(27% 0.06 243.1)
#138BD4 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) | #688ED7 | 0.063 |
| Deuteranopia (no green cones) | #4D7DD3 | 0.046 |
| Tritanopia (no blue cones) | #009DA5 | 0.100 |
| Achromatopsia (no color) | #858585 | 0.146 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #138BD4
#138BD4
oklch(61.3% 0.145 243.8)
- #BD6F00
#BD6F00
oklch(61.4% 0.139 63.9)
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 #138BD4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Water Blue #0E87CC ΔE 0.015
- Dark Sky Blue #448EE4 ΔE 0.038
- Cool Blue #4984B8 ΔE 0.048
- Steel Blue #4682B4 ΔE 0.053
- Blue NCS #118AB2 ΔE 0.053
- Windows Blue #3778BF ΔE 0.055
- Chefchaouen Blue #4895EF ΔE 0.058
- Dodger Blue #1E90FF ΔE 0.065
Use #138BD4 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.