Steelblue4
steelblue4 · #36648B
HEX
#36648B
RGB
rgb(54, 100, 139)
CMYK
cmyk(61%, 28%, 0%, 45%)
HSL
hsl(208, 44%, 38%)
LAB
lab(40.8, -3.3, -26.3)
What is Steelblue4?
Steelblue4 is the steelblue4 reference in the X11 named colors. Its sRGB value is #36648B (rgb 54, 100, 139). It sits in the blue family. Historical X Window System color names — the numbered 1-4 lightness variants of the classic xorg-server rgb.txt palette. See disclaimer for accuracy and trademark notes.
Accessibility
WCAG 2.1 contrast checks for Steelblue4 as a background.
Black text on this color
White text on this color
Shades, tints & tonal scale of Steelblue4
An 11-step tonal scale derived from Steelblue4 (#36648B). Click any swatch to copy its HEX. Use these as a starting point for design tokens, hover states, and disabled states in a design system.
50
#EFF3F6
#EFF3F6
100
#DFE6EC
#DFE6EC
200
#BFCDDA
#BFCDDA
300
#9BB2C5
#9BB2C5
400
#688BA8
#688BA8
500
#36648B
#36648B
600
#2E5576
#2E5576
700
#23415A
#23415A
800
#182D3F
#182D3F
900
#0E1923
#0E1923
950
#060C11
#060C11
Lighter tints (mixed with white)
15%
#768BA4
30%
#9BA8B8
45%
#B6BFCA
60%
#CED3DA
75%
#E2E5E9
Darker shades (mixed with black)
15%
#325D81
30%
#2D5476
45%
#274B69
60%
#20405A
75%
#183248
Color harmonies for Steelblue4
Classic color-theory harmonies derived from rotating the hue of Steelblue4. Use these to build accent palettes, brand systems, and accessible UI color pairings.
Complementary
180° opposite — strongest contrast
#36648B
#36648B
#8C5E36
#8C5E36
Triadic
Three colors 120° apart
#36648B
#36648B
#8C3664
#8C3664
#648C36
#648C36
Analogous
Two neighbors ±30° on the wheel
#368C89
#368C89
#36648B
#36648B
#36398C
#36398C
Split-complementary
Base + two colors flanking its complement
#36648B
#36648B
#8C3639
#8C3639
#8C8936
#8C8936
Tetradic
Two complementary pairs
#36648B
#36648B
#5E368C
#5E368C
#8C5E36
#8C5E36
#648C36
#648C36
Square
Four colors evenly spaced 90° apart
#36648B
#36648B
#89368C
#89368C
#8C5E36
#8C5E36
#398C36
#398C36
Steelblue4 in every color space
Full conversion of Steelblue4 across the color spaces designers and developers actually use — including OKLCH (the perceptually-uniform space that powers Tailwind v4 and CSS Color Module Level 4) and HWB.
HEX
#36648B
RGB
rgb(54, 100, 139)
CMYK
cmyk(61%, 28%, 0%, 45%)
HSL
hsl(208, 44%, 38%)
HSV
hsv(208, 61%, 55%)
HWB
hwb(208 21% 45%)
CIE Lab
lab(40.8 -3.3 -26.3)
OKLCH
oklch(48.8% 0.081 246.0)
XYZ (D65)
xyz(10.74, 11.76, 26.13)
Copy-ready code for Steelblue4
Drop-in snippets for CSS, Tailwind, Sass, iOS Swift, and Android XML. Click the copy button on any snippet to put it on your clipboard.
CSS
color: #36648B;
background-color: #36648B;CSS variable
:root {
--color-steelblue4: #36648B;
}Tailwind config
// tailwind.config.js
colors: {
'steelblue4': '#36648B',
}Sass
$color-steelblue4: #36648B;Swift UIColor
UIColor(red: 0.212, green: 0.392, blue: 0.545, alpha: 1.0)Android XML
<color name="steelblue4">#36648B</color>Closest match in every color system
The nearest Steelblue4 equivalent in every other color system on this site, ranked by ΔE2000 perceptual distance. Useful when translating between design-system, web-standard, and industrial color references.
Closest in X11 named colors
Top 6 ΔE2000-closest entries within the same collection.
Closest Pantone matches
Top 6 ΔE2000-closest Pantone references. Cross-system matching is approximate — see disclaimer.
Closest RAL Classic matches
Top 6 ΔE2000-closest RAL Classic references for industrial coating cross-reference.
RAL 5007
#3E5F8A
Brilliant blue
RAL 5023
#49678D
Distant blue
RAL 5019
#1B5583
Capri blue
RAL 5015
#2271B3
Sky blue
RAL 5000
#354D73
Violet blue
RAL 5014
#606E8C
Pigeon blue
FAQ about Steelblue4
What is the HEX code for Steelblue4?
Steelblue4 (steelblue4) has the HEX code #36648B. In RGB it is rgb(54, 100, 139), and in CMYK it is cmyk(61%, 28%, 0%, 45%).
What is the OKLCH value of Steelblue4?
Steelblue4 converts to oklch(0.488 0.081 246.0). OKLCH is the perceptually uniform color space used by Tailwind v4 and CSS Color Module Level 4.
Is Steelblue4 accessible for body text?
Used as a background, Steelblue4 has a contrast ratio of 3.35:1 with black text and 6.26:1 with white text. WCAG 2.1 AA requires 4.5:1 for normal text. The current recommendation is to use white text and verify in real UI context.
What is the closest Pantone to Steelblue4?
The closest Pantone reference to Steelblue4 by ΔE2000 perceptual distance is Pantone 307 C (#0067A5). Cross-system Pantone matching is approximate; for color-critical print work, verify with a physical Pantone guide.
What is the closest RAL color to Steelblue4?
The closest RAL Classic reference to Steelblue4 by ΔE2000 distance is RAL 5007 (Brilliant blue, #3E5F8A). RAL is a German industrial coating standard commonly used for paint, powder coat, and architectural specification.
What is the complementary color of Steelblue4?
The complementary color (180° opposite on the HSL color wheel) of Steelblue4 is #8C5E36. Use it for high-contrast accents, error states, or call-to-action pairings.
Data provenance & source
X11 named colors (xorg rgb.txt)
The historical X11 color name list shipped in the xorg-server rgb.txt file. Roughly 550 entries covering classic computing color names like 'PapayaWhip', 'MediumAquamarine', and 'DarkSlateGray'. Many CSS named colors originate here. Use as a reference for legacy and creative color names. Most modern CSS implementations accept these names directly.
- Source type
- derived
- Confidence
- high
- License
- MIT/X11 license (X Consortium)
- Last reviewed
- 2026-05-24
Workflow tags
X11 colors are sRGB digital values from a 1980s color system. For print, convert to a process-appropriate color and proof against substrate.