The main difference between Ruby and Espresso is hue — Ruby is a warm pink, while Espresso is a warm red. Ruby (#E0115F) has an HSL of 337°, 86%, 47%, whereas Espresso (#3C1414) sits at 0°, 50%, 16%.
Ruby (#E0115F) is a medium, vivid pink with a warm undertone — it feels balanced, versatile and bright, energetic, eye-catching.
Espresso (#3C1414) is a very dark, moderately saturated red with a warm undertone — it feels deep, heavy, grounded and balanced in intensity.
Text legibility depends on the contrast ratio between foreground and background. WCAG 2.1 AA requires at least 4.5:1 for normal text and 3:1 for large text; AAA requires 7:1. Use these numbers to choose accessible combinations for your design.
Each color has a dedicated page with shades, tints, CSS name, pairings, and color psychology.