turquoise 4

Turquoise 4 (#00868B) is the darkest variant in the X11 Turquoise series, a deep teal where the bright, gem-like quality of the lighter variants has given way to a rich, serious blue-green reminiscent of deep ocean water. Used in professional design contexts requiring teal depth, conservation-themed design, and grounding dark accents in turquoise palettes, it provides the most authoritative and grounded expression of the turquoise family.

Dark cyans and deep aquas convey depth, reliability, and technical mastery. They carry the trustworthiness of blue with a modern, slightly warmer edge from their green component. These tones suggest specialized expertise and sophisticated engineering.

Dark cyan works for cybersecurity brands, developer platforms, and data infrastructure companies. It creates striking dark-mode accents and terminal-style interfaces that feel technical yet approachable. Pair it with lighter cyan highlights and neutral grays for a layered, depth-rich design system.