Exploring the Color #637B6B

#637B6B sits at 140° on the color wheel, placing it in the spring green family of the cool half of the spectrum. With 11% saturation and 44% lightness, it reads as a heavily muted, shadowed tone — a quiet, restrained presence that recedes rather than competes. Its RGB mix of 99, 123, 107 produces a 4.59:1 contrast ratio against white, which clears WCAG AA for body text in that pairing.

In RGB space #637B6B is a close cousin of CSS dim gray — about 19 units away from #696969. Designers reach for spring green hues at this saturation when the brief calls for restraint and atmosphere, and at this lightness when they want a present, comfortable mid-canvas voice. On screen the cool cast tends to pair best with warm neutrals in the 25°-45° range to add life.

Darkening Shades

Lightening Shades