#537FBB
Closest named color: Cool Blue (#4984B8). oklch(59.1% 0.105 256.4), rgb(83, 127, 187).
Aa
Black text reads best on this color (5.12:1).
About this color
#537FBB is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.105 and its hue 256°. Its hue sits on the cool side of the wheel. The nearest named color is Cool Blue (#4984B8), ΔE 0.018 away. Black text reads best on it, at 5.12:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.105) |
| Temperature | cool |
| Nearest name | Cool Blue (#4984B8) |
| Black text | 5.12:1 |
| White text | 4.10:1 |
Values
| HEX | #537FBB |
| RGB | rgb(83, 127, 187) |
| HSL | hsl(215, 43%, 53%) |
| OKLCH | oklch(59.1% 0.105 256.4) |
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 #537FBB | 4.10:1 | AA large text | Lc -73.5 | Content text, not long reading |
| Black text on #537FBB | 5.12:1 | AA | Lc 36.1 | Non-text elements, placeholder text |
| #537FBB text on white | 4.10:1 | AA large text | Lc 68.0 | Content text, not long reading |
| #537FBB text on black | 5.12:1 | AA | Lc -33.6 | 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 600.
-
Step 50
50
#F3F6FA
oklch(97.2% 0.006 255.5)
-
Step 100
100
#E4EAF3
oklch(93.5% 0.014 258.3)
-
Step 200
200
#CEDAEB
oklch(88.4% 0.027 257)
-
Step 300
300
#ADC2DF
oklch(80.8% 0.047 256.5)
-
Step 400
400
#82A3D0
oklch(70.8% 0.076 256.3)
-
Step 500
500
#628BC3
oklch(63% 0.096 256.4)
-
Step 600
600 (this color)
#537FBB
oklch(59.1% 0.105 256.4)
-
Step 700
700
#3A6297
oklch(49.2% 0.097 256)
-
Step 800
800
#30507A
oklch(42.7% 0.08 255.7)
-
Step 900
900
#2B4263
oklch(37.6% 0.064 257.4)
-
Step 950
950
#19273A
oklch(27% 0.041 256.3)
#537FBB 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) | #6783BE | 0.027 |
| Deuteranopia (no green cones) | #5A79BA | 0.017 |
| Tritanopia (no blue cones) | #0B8C94 | 0.093 |
| Achromatopsia (no color) | #7D7D7D | 0.105 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #537FBB
#537FBB
oklch(59.1% 0.105 256.4)
- #A1742B
#A1742B
oklch(59.1% 0.105 75.9)
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 #537FBB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cool Blue #4984B8 ΔE 0.018
- Steel Blue #4682B4 ΔE 0.020
- Off Blue #5684AE ΔE 0.028
- Dusty Blue #5A86AD ΔE 0.034
- Windows Blue #3778BF ΔE 0.036
- Faded Blue #658CBB ΔE 0.045
- Water Blue #0E87CC ΔE 0.047
- Stormy Blue #507B9C ΔE 0.048
Use #537FBB 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.