Dark Red Color / Colour Code #660019
This page shows the hex color code for dark red (#660019). The colour is a red tone with 100% saturation and 20% lightness. Explore its conversions, colour palettes, gradients, accessibility data, and CSS code below.
Color Conversions
Accessibility Contrast
WCAG contrast ratios for #660019 against common backgrounds.
Complementary Colors
#660019 paired with its color wheel opposite for maximum contrast.
Analogous Colors
Hues at 315, 345, and 15 degrees for harmonious combinations.
Triadic Palette
Three colors at 345, 105, and 225 degrees.
Color Palettes Using #660019
Five shades at lightness levels 15% through 85% while keeping hue at 345 and saturation at 100%. Use the darkest shade for text and the lightest for backgrounds to build a cohesive single-hue design system.
Adjacent hues from 345 to 30 degrees create a warm, unified palette. This analogous scheme works for marketing materials, seasonal campaigns, and any design that needs visual warmth without clashing colors.
Combines the base color at hue 345 with its complement at 165 and two adjacent cool tones. This split-complementary approach provides strong visual contrast while remaining more balanced than a pure complementary scheme.
Five evenly spaced hues at 40% saturation and 80% lightness. Pastels are gentle on the eyes and work well for dashboards, onboarding screens, category tags, and any interface where multiple distinct colors are needed without visual aggression.
Shades & Tints of #660019
Lightness variations at hue 345 and 100% saturation.
CSS Gradients with #660019
Design Use Cases for #660019
High-Impact Accent
With 100% saturation, #660019 is highly vivid. Reserve this for elements that need maximum attention: primary action buttons, notification badges, error states, or promotional banners. Use sparingly alongside neutral tones to avoid visual fatigue.
Deep Accent & Text Color
#660019 at 20% lightness is dark enough for readable body text on light backgrounds while retaining its red character. Use for headings, emphasized text, or deep accent borders. It provides contrast without the harshness of pure black.
Urgency & Energy Signaling
#660019 falls in the red spectrum (hue 345). Red triggers urgency and excitement, making it effective for sale badges, countdown timers, error messages, and "limited time" labels. In data visualization, use it to flag negative values or critical thresholds.
Gradient Pairing
Create a gradient from #660019 (hue 345) to its complement at hue 165. For a subtler effect, try pairing with an analogous color at hue 15. Use CSS: background: linear-gradient(135deg, #660019, #00664d);
CSS Code for #660019
Similar Colors
Colors visually similar to #660019 based on RGB, lightness, and hue variations.
Use This Color in Design Tools
Apply #660019 across image editing and color design tools.
About Dark Red (#660019)
#660019 is a red color (colour) with RGB channel values of 102 red, 0 green, and 25 blue. The red channel is dominant by a ratio of 102.0:1 over the weakest channel. In HSL terms, the hue sits at 345 degrees with 100% saturation and 20% lightness, placing it in the warm range of the colour spectrum.
The perceived brightness of #660019 is 33/255 using the ITU-R BT.601 luma formula (0.299R + 0.587G + 0.114B). This appears dark to the human eye, so pair it with light text for adequate readability. For print production, the CMYK equivalent is 0% cyan, 100% magenta, 75% yellow, and 60% key (black).
The WCAG contrast ratio of #660019 against white is 13.30:1 and against black is 1.58:1. This exceeds the AAA requirement (7:1) for normal text on white, making it excellent for body text and small UI labels on light backgrounds.
The complementary colour #00664D creates maximum visual tension when paired with #660019. For more harmonious color combinations, use the analogous colours #66004C and #661A00, which sit 30 degrees on either side of the hue wheel. To build a complete design system, start with the monochromatic scale above for consistent shade variations, then add one complementary or triadic accent for interactive elements.
How to Explore Color #660019
- Enter your color value in HEX format.
- The tool converts it to RGB, HSL, CMYK format in real time.
- Copy the converted value to your clipboard.
What is HEX to RGB, HSL, CMYK color conversion
Converting from HEX to RGB, HSL, CMYK translates a color value between two different color models. Different color models are used in web design (HEX, RGB), print (CMYK), and color theory (HSL, HSV).
Related Tools & Colors
Frequently Asked Questions
- What color / colour is #660019?
- #660019 is Dark Red, a red color (colour) with RGB(102, 0, 25), HSL(345, 100%, 20%), and CMYK(0%, 100%, 75%, 60%). Its perceived brightness is 33/255.
- Is #660019 accessible for text?
- Against white, #660019 has a contrast ratio of 13.30:1 (passes AA for normal text). Against black, it has 1.58:1 (fails AA). Use the contrast checker tool for custom background pairings.
- What colours pair well with #660019?
- The complementary colour is #00664D (hue 165). For subtle color combinations, use analogous colours #66004C and #661A00. The triadic palette adds #196600 and #001966 for vibrant variety.
- How do I use #660019 in CSS?
- Use any format: color: #660019; or rgb(102, 0, 25); or hsl(345, 100%, 20%). For CSS custom properties: --color-primary: 345 100% 20%; then use it as hsl(var(--color-primary)).
- Is this color / colour explorer free?
- Yes, completely free with no signup required. All colour calculations run in your browser. You can explore any valid hex color code, not just the pre-generated palette.