#3977A4
Closest named color: Flat Blue (#3C73A8). oklch(54.8% 0.095 242.7), rgb(57, 119, 164).
Aa
White text reads best on this color (4.82:1).
About this color
#3977A4 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 55%, its chroma 0.095 and its hue 243°. Its hue sits on the cool side of the wheel. The nearest named color is Flat Blue (#3C73A8), ΔE 0.015 away. White text reads best on it, at 4.82:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | moderately saturated (0.095) |
| Temperature | cool |
| Nearest name | Flat Blue (#3C73A8) |
| Black text | 4.34:1 |
| White text | 4.82:1 |
Values
| HEX | #3977A4 |
| RGB | rgb(57, 119, 164) |
| HSL | hsl(205, 48%, 43%) |
| OKLCH | oklch(54.8% 0.095 242.7) |
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 #3977A4 | 4.82:1 | AA | Lc -78.7 | Fine for body text |
| Black text on #3977A4 | 4.34:1 | AA large text | Lc 30.8 | Non-text elements, placeholder text |
| #3977A4 text on white | 4.82:1 | AA | Lc 73.3 | Content text, not long reading |
| #3977A4 text on black | 4.34:1 | AA large text | Lc -28.4 | 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
#CCDBE8
oklch(88.4% 0.024 244.2)
-
Step 300
300
#A9C5DB
oklch(81% 0.043 241.8)
-
Step 400
400
#7BA6C8
oklch(70.7% 0.068 242.7)
-
Step 500
500
#5890BA
oklch(63.2% 0.087 242.3)
-
Step 600
600 (this color)
#3977A4
oklch(54.8% 0.095 242.7)
-
Step 700
700
#2D668F
oklch(49.1% 0.089 242.8)
-
Step 800
800
#275374
oklch(42.7% 0.073 243.4)
-
Step 900
900
#24455D
oklch(37.7% 0.057 241.9)
-
Step 950
950
#162937
oklch(27.2% 0.036 241.7)
#3977A4 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) | #6378A6 | 0.047 |
| Deuteranopia (no green cones) | #546DA3 | 0.037 |
| Tritanopia (no blue cones) | #008287 | 0.070 |
| Achromatopsia (no color) | #727272 | 0.095 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3977A4
#3977A4
oklch(54.8% 0.095 242.7)
- #986431
#986431
oklch(54.9% 0.095 62.9)
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 #3977A4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Flat Blue #3C73A8 ΔE 0.015
- Muted Blue #3B719F ΔE 0.017
- Dull Blue #49759C ΔE 0.018
- Cerulean #457B9D ΔE 0.022
- Nice Blue #107AB0 ΔE 0.026
- Stormy Blue #507B9C ΔE 0.030
- Ocean Blue #03719C ΔE 0.037
- Metallic Blue #4F738E ΔE 0.037
Use #3977A4 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.