You can change the color saturation (vividness or color purity) of all colors by adjusting the Vibrance and Saturation controls in the Basic tab. (To adjust saturation for a specific range of colors, use the controls in the HSL / Grayscale tab.)

Vibrance

Adjusts the saturation so that clipping is minimized as colors approach full saturation, changing the saturation of all lower-saturated colors with less impact on the higher-saturated colors. Vibrance also prevents skin tones from becoming oversaturated.

Saturation

Adjusts the saturation of all image colors equally from ‑100 (monochrome) to +100 (double the saturation).