#377AA8
Closest named color: Flat Blue (#3C73A8). oklch(55.7% 0.099 241.6), rgb(55, 122, 168).
Aa
White text reads best on this color (4.65:1).
About this color
#377AA8 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 56%, its chroma 0.099 and its hue 242°. Its hue sits on the cool side of the wheel. The nearest named color is Flat Blue (#3C73A8), ΔE 0.020 away. White text reads best on it, at 4.65:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | moderately saturated (0.099) |
| Temperature | cool |
| Nearest name | Flat Blue (#3C73A8) |
| Black text | 4.51:1 |
| White text | 4.65:1 |
Values
| HEX | #377AA8 |
| RGB | rgb(55, 122, 168) |
| HSL | hsl(204, 51%, 44%) |
| OKLCH | oklch(55.7% 0.099 241.6) |
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 #377AA8 | 4.65:1 | AA | Lc -77.5 | Fine for body text |
| Black text on #377AA8 | 4.51:1 | AA | Lc 32.0 | Non-text elements, placeholder text |
| #377AA8 text on white | 4.65:1 | AA | Lc 72.1 | Content text, not long reading |
| #377AA8 text on black | 4.51:1 | AA | Lc -29.6 | Dividers and decoration only |
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 600.
-
Step 50
50
#F2F6F9
oklch(97.1% 0.006 239.8)
-
Step 100
100
#E3EBF2
oklch(93.6% 0.013 244.3)
-
Step 200
200
#CCDCE8
oklch(88.6% 0.024 240.1)
-
Step 300
300
#A8C5DB
oklch(80.9% 0.044 240.9)
-
Step 400
400
#79A7C9
oklch(70.8% 0.07 241)
-
Step 500
500
#5490BC
oklch(63.1% 0.091 242)
-
Step 600
600 (this color)
#377AA8
oklch(55.7% 0.099 241.6)
-
Step 700
700
#296690
oklch(49% 0.092 242.2)
-
Step 800
800
#235475
oklch(42.8% 0.076 241.2)
-
Step 900
900
#22455E
oklch(37.6% 0.059 241.7)
-
Step 950
950
#152937
oklch(27.1% 0.037 240.5)
#377AA8 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) | #657AAA | 0.049 |
| Deuteranopia (no green cones) | #566FA7 | 0.041 |
| Tritanopia (no blue cones) | #00858A | 0.070 |
| Achromatopsia (no color) | #747474 | 0.099 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #377AA8
#377AA8
oklch(55.7% 0.099 241.6)
- #9D6531
#9D6531
oklch(55.7% 0.099 61.2)
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 #377AA8, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Flat Blue #3C73A8 ΔE 0.020
- Cerulean #457B9D ΔE 0.021
- Nice Blue #107AB0 ΔE 0.023
- Dull Blue #49759C ΔE 0.024
- Muted Blue #3B719F ΔE 0.026
- Stormy Blue #507B9C ΔE 0.030
- Steel Blue #4682B4 ΔE 0.032
- Windows Blue #3778BF ΔE 0.038
Use #377AA8 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.