Exploring the Color #639CCB

#639CCB sits at 207° on the color wheel, placing it in the azure family of the cool half of the spectrum. With 50% saturation and 59% lightness, it reads as a moderately saturated, light tone — a balanced mid-energy presence that sits comfortably alongside other UI tones. Its RGB mix of 99, 156, 203 produces a 7.15:1 contrast ratio against black, which clears WCAG AAA for body text in that pairing.

In RGB space #639CCB is a clear variant of CSS steel blue — about 45 units away from #4682B4. Designers reach for azure hues at this saturation when the brief calls for a conversational, mid-energy register, 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