#2399CB
Closest named color: Blue NCS (#118AB2). oklch(64.4% 0.123 232.5), rgb(35, 153, 203).
Aa
Black text reads best on this color (6.49:1).
About this color
#2399CB is a medium-light, moderately saturated blue. In OKLCH its lightness is 64%, its chroma 0.123 and its hue 232°. Its hue sits on the cool side of the wheel. The nearest named color is Blue NCS (#118AB2), ΔE 0.053 away. Black text reads best on it, at 6.49:1.
| Hue family | Blues |
| Lightness | medium-light (64%) |
| Chroma | moderately saturated (0.123) |
| Temperature | cool |
| Nearest name | Blue NCS (#118AB2) |
| Black text | 6.49:1 |
| White text | 3.23:1 |
Values
| HEX | #2399CB |
| RGB | rgb(35, 153, 203) |
| HSL | hsl(198, 71%, 47%) |
| OKLCH | oklch(64.4% 0.123 232.5) |
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 #2399CB | 3.23:1 | AA large text | Lc -64.6 | Content text, not long reading |
| Black text on #2399CB | 6.49:1 | AA | Lc 44.9 | Non-text elements, placeholder text |
| #2399CB text on white | 3.23:1 | AA large text | Lc 59.2 | Large or bold text, headings |
| #2399CB text on black | 6.49:1 | AA | Lc -42.6 | 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
#F0F6FA
oklch(97% 0.008 236.6)
-
Step 100
100
#DFECF4
oklch(93.6% 0.018 234.5)
-
Step 200
200
#C4DEEC
oklch(88.6% 0.034 231.2)
-
Step 300
300
#9AC8E1
oklch(80.9% 0.06 232.2)
-
Step 400
400
#5DABD3
oklch(70.7% 0.097 232.7)
-
Step 500
500 (this color)
#2399CB
oklch(64.4% 0.123 232.5)
-
Step 600
600
#007EAB
oklch(55.7% 0.114 232.4)
-
Step 700
700
#006990
oklch(49% 0.101 232.9)
-
Step 800
800
#005677
oklch(42.6% 0.088 233.1)
-
Step 900
900
#004864
oklch(37.8% 0.078 232.8)
-
Step 950
950
#052A3B
oklch(26.9% 0.051 233.3)
#2399CB 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) | #8097CD | 0.079 |
| Deuteranopia (no green cones) | #6A88CA | 0.067 |
| Tritanopia (no blue cones) | #00A6AA | 0.072 |
| Achromatopsia (no color) | #8F8F8F | 0.123 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #2399CB
#2399CB
oklch(64.4% 0.123 232.5)
- #C77640
#C77640
oklch(64.4% 0.123 52.4)
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 #2399CB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Blue NCS #118AB2 ΔE 0.053
- Water Blue #0E87CC ΔE 0.054
- Faded Blue #658CBB ΔE 0.056
- Dark Sky Blue #448EE4 ΔE 0.057
- Cool Blue #4984B8 ΔE 0.059
- Chefchaouen Blue #4895EF ΔE 0.064
- Dusty Blue #5A86AD ΔE 0.065
- Steel Blue #4682B4 ΔE 0.066
Use #2399CB 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.