Stripe Indigo
Stripe Indigo (#635BFF) is a true blue with a cool character. It leans cool, sitting on the blue, green, and violet side of the wheel. Quiet and dependable, a fit for product UI and data visualization. Its HSL profile (243°, 100%, 68%) places it in the highly saturated band at a mid lightness. Best used in small doses, like logos, CTAs, focus rings, or highlight text, where its saturation becomes a feature rather than noise. For a confident two-color system, pair it with its complementary yellow. For something softer, pull in its analogous neighbors on either side of the wheel. The blue-purple of Stripe's 2020 rebrand, replacing an earlier #32325D. The new shade paired with Stripe's famously fluid developer-doc gradients and became shorthand for "modern fintech UI."