#1978D9
Closest named color: Windows Blue (#3778BF). oklch(57.4% 0.17 253.9), rgb(25, 120, 217).
Aa
Black text reads best on this color (4.72:1).
About this color
#1978D9 is a medium-dark, vivid blue. In OKLCH its lightness is 57%, its chroma 0.170 and its hue 254°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.042 away. Black text reads best on it, at 4.72:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | vivid (0.170) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.72:1 |
| White text | 4.43:1 |
Values
| HEX | #1978D9 |
| RGB | rgb(25, 120, 217) |
| HSL | hsl(210, 79%, 47%) |
| OKLCH | oklch(57.4% 0.17 253.9) |
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 #1978D9 | 4.43:1 | AA large text | Lc -75.7 | Fine for body text |
| Black text on #1978D9 | 4.72:1 | AA | Lc 33.9 | Non-text elements, placeholder text |
| #1978D9 text on white | 4.43:1 | AA large text | Lc 70.2 | Content text, not long reading |
| #1978D9 text on black | 4.72:1 | AA | Lc -31.5 | 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 600.
-
Step 50
50
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E0EBF9
oklch(93.6% 0.022 254.4)
-
Step 200
200
#C6DBF5
oklch(88.4% 0.042 253.8)
-
Step 300
300
#9FC4F2
oklch(81% 0.077 254.1)
-
Step 400
400
#68A4EB
oklch(70.8% 0.122 253.5)
-
Step 500
500
#3C8BE5
oklch(63.2% 0.156 253.9)
-
Step 600
600 (this color)
#1978D9
oklch(57.4% 0.17 253.9)
-
Step 700
700
#0060B6
oklch(49.2% 0.156 253.8)
-
Step 800
800
#074E94
oklch(42.6% 0.131 254.1)
-
Step 900
900
#124276
oklch(37.7% 0.102 253.7)
-
Step 950
950
#0D2745
oklch(27% 0.064 254)
#1978D9 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) | #4480DD | 0.038 |
| Deuteranopia (no green cones) | #1470D7 | 0.022 |
| Tritanopia (no blue cones) | #008F9E | 0.125 |
| Achromatopsia (no color) | #787878 | 0.170 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1978D9
#1978D9
oklch(57.4% 0.17 253.9)
- #A26C00
#A26C00
oklch(57.4% 0.121 74.6)
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 #1978D9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.042
- Cerulean Blue #056EEE ΔE 0.044
- Royal Blue #4169E1 ΔE 0.045
- Water Blue #0E87CC ΔE 0.049
- Clear Blue #247AFD ΔE 0.055
- Mid Blue #276AB3 ΔE 0.065
- Nice Blue #107AB0 ΔE 0.066
- Neon Blue #4361EE ΔE 0.069
Use #1978D9 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.