#42738B
Closest named color: Metallic Blue (#4F738E). oklch(53.1% 0.065 231), rgb(66, 115, 139).
Aa
White text reads best on this color (5.17:1).
About this color
#42738B is a medium-dark, muted blue. In OKLCH its lightness is 53%, its chroma 0.065 and its hue 231°. Its hue sits on the cool side of the wheel. The nearest named color is Metallic Blue (#4F738E), ΔE 0.016 away. White text reads best on it, at 5.17:1.
| Hue family | Blues |
| Lightness | medium-dark (53%) |
| Chroma | muted (0.065) |
| Temperature | cool |
| Nearest name | Metallic Blue (#4F738E) |
| Black text | 4.05:1 |
| White text | 5.17:1 |
Values
| HEX | #42738B |
| RGB | rgb(66, 115, 139) |
| HSL | hsl(200, 36%, 40%) |
| OKLCH | oklch(53.1% 0.065 231) |
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 #42738B | 5.17:1 | AA | Lc -80.9 | Fine for body text |
| Black text on #42738B | 4.05:1 | AA large text | Lc 28.5 | Dividers and decoration only |
| #42738B text on white | 5.17:1 | AA | Lc 75.5 | Fine for body text |
| #42738B text on black | 4.05:1 | AA large text | Lc -26.2 | 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
#F3F6F8
oklch(97.1% 0.004 236.5)
-
Step 100
100
#E4EBEE
oklch(93.6% 0.009 225.1)
-
Step 200
200
#CFDBE2
oklch(88.4% 0.016 233)
-
Step 300
300
#AEC5D0
oklch(81% 0.029 228.2)
-
Step 400
400
#83A6B9
oklch(70.6% 0.047 232)
-
Step 500
500
#6390A7
oklch(62.9% 0.06 231.2)
-
Step 600
600 (this color)
#42738B
oklch(53.1% 0.065 231)
-
Step 700
700
#3A677D
oklch(49.1% 0.061 231)
-
Step 800
800
#315466
oklch(42.7% 0.05 232)
-
Step 900
900
#2B4653
oklch(37.8% 0.04 229.9)
-
Step 950
950
#1A2930
oklch(27.1% 0.024 228.7)
#42738B 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) | #67718C | 0.045 |
| Deuteranopia (no green cones) | #5D6A8B | 0.039 |
| Tritanopia (no blue cones) | #187A7B | 0.048 |
| Achromatopsia (no color) | #6D6D6D | 0.065 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #42738B
#42738B
oklch(53.1% 0.065 231)
- #8B6149
#8B6149
oklch(53.1% 0.066 50.6)
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 #42738B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Metallic Blue #4F738E ΔE 0.016
- Dull Blue #49759C ΔE 0.029
- Cerulean #457B9D ΔE 0.033
- Muted Blue #3B719F ΔE 0.035
- Sea Blue #047495 ΔE 0.036
- Ocean #017B92 ΔE 0.037
- Stormy Blue #507B9C ΔE 0.037
- Deep Aqua #08787F ΔE 0.044
Use #42738B 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.