≈ Castro

Castro (#38232A) is a dark, neutral red with a warm feel. It has a hue angle of 340° and a lightness of 29%. As a neutral it supports other colors rather than competing with them.

Red is the color people notice first. It raises attention and energy, and is tied to appetite, passion and urgency, which is why it works for calls to action and sale banners, and why too much of it can feel tense. As a dark shade, Castro feels weighty and serious.

In much of the West red stands for love, danger and stop. In China and many other East Asian cultures it is the color of luck, celebration and prosperity.

Castro is a flexible base. It carries white text well, so it works as a button, header or badge background. Pair it with its tints and shades for a complete scale.

• Calls to action and sale banners
• Food and drink branding
• Error and alert states
• Festive and celebration design

Red ochre is among the oldest pigments, found in prehistoric cave art. Later reds came from madder root, cochineal insects and vermilion; the synthetic dye alizarin, made in 1868, replaced madder.

White text on Castro has a contrast ratio of 14.56:1 (AAA); black text has 1.44:1 (fails). WCAG AA needs 4.5:1 for body text and 3:1 for large text and interface parts. Red and green are the pair most often confused in color blindness, so never use this color alone to mean success or error: add an icon or label.