#042558 Color
#042558 is rgb(4, 37, 88) in RGB, hsl(216, 91%, 18%) in HSL, and about cmyk(95%, 58%, 0%, 65%) in CMYK. It has no registered color name of its own — the closest is Dark Midnight Blue (#003366), clearly related but distinguishable side by side at ΔE 7.24. White text is the more readable choice on this background.
#042558rgb(4, 37, 88)hsl(216, 91%, 18%)hsv(216, 95%, 35%)cmyk(95%, 58%, 0%, 65%)oklch(27.8% 0.1 259.3)lab(15.20% 6.52 -34.72)lch(15.20% 35.33 280.64)What #042558 Is Called
Most hex codes have no name: there are 16.7 million of them and a few thousand registered names. These are the named colors nearest to #042558, ordered by CIE76 distance in CIELAB. Anything under about ΔE 2 is a difference most people cannot see.
Browse the full index of named colors A-Z or every blue in the library.
#042558 Channel Values
How #042558 breaks down in each color model. Hue is measured in degrees around the color wheel; saturation, lightness, and the CMYK inks are percentages.
| Model | Channels | Notes |
|---|---|---|
| RGB | R 4 · G 37 · B 88 | 8-bit channels as sent to the display |
| HSL | H 216° · S 91% · L 18% | Easiest model for building lighter and darker variants |
| HSV | H 216° · S 95% · V 35% | Matches the picker in most design tools |
| CMYK | C 95% · M 58% · Y 0% · K 65% | Approximate ink mix; confirm with an ICC profile before printing |
| Luminance | 14.89:1 vs white · 1.41:1 vs black | WCAG 2.2 relative-luminance contrast ratios |
Text Contrast & Accessibility
WCAG 2.2 contrast ratios for text on a #042558 background. AA requires 4.5:1 for normal text and 3:1 for large text; AAA requires 7:1. Contrast is one check, not a full accessibility review.
Need a specific ratio against another background? Open #042558 in the contrast checker.
Colors That Go With #042558
Pairings derived from color-wheel relationships. The complementary color sits opposite #042558; analogous colors sit beside it; triadic and split-complementary sets spread evenly around the wheel. Select any swatch for its own breakdown.
Tints & Shades of #042558
Lighter tints and darker shades built by moving the lightness channel while holding hue and saturation, which is what you want for hover states, backgrounds, and text variants.
Want a full 50-950 ramp with semantic roles? Generate design tokens from #042558.
How #042558 Looks with Color Vision Deficiency
Simulated with the Viénot, Brettel & Mollon LMS projection model. Anomalous types are rendered as partial versions of the matching dichromacy, which is an approximation rather than a per-person clinical model.
#042558#212158#192358#1E1E58#162158#002F2F#002B43#272727Using #042558 in Code
Copy-ready declarations for the places this color usually ends up.
--color-042558: #042558;background-color: #042558;colors: { 'color-042558': '#042558' }Color(red: 0.016, green: 0.145, blue: 0.345)<color name="color_042558">#042558</color>fill="#042558"More Blue Colors
#042558 sits in the blue family. These are its neighbours across that family's full range, each with its own breakdown.
#042558 Frequently Asked Questions
What color is #042558?
#042558 is a darkest blue — rgb(4, 37, 88) in RGB and hsl(216, 91%, 18%) in HSL. It carries no registered color name of its own; the closest named color is Dark Midnight Blue (#003366), which is clearly related but distinguishable side by side at a CIE76 distance of 7.24.
What is the RGB value of #042558?
#042558 is rgb(4, 37, 88) — red 4, green 37, and blue 88 on the 0-255 scale.
What is the CMYK value of #042558?
#042558 converts to approximately cmyk(95%, 58%, 0%, 65%). CMYK output is a mathematical approximation for planning; confirm production print colors with your printer and ICC profile.
Should text on #042558 be black or white?
White text is the more readable choice. #042558 scores 14.89:1 against white and 1.41:1 against black, and WCAG 2.2 asks for at least 4.5:1 for normal body text.
Can I write #042558 as a CSS color keyword?
No. #042558 is not one of the CSS color keywords, so it has to be written as a hex, rgb() or hsl() value. The closest keyword is darkslateblue (#483D8B) at a CIE76 distance of 22.67, which is visibly different.
Open #042558 in a Tool
Keep exploring: every blue in the color library, the guide to shades of blue, or the full color library.