Replace One Swatch with Another

If you've used a color or gradient for various objects and you want to replace that color with another one, press-and-hold the Option key (PC: Alt key), and drag the new replacement swatch over the original swatch. If you're using global color, meaning you've checked Global in the New Swatch dialog when you created the color, all objects using the original global color will change to the new color. (Note: Doing this will remove the original swatch from the palette. So, if you want to keep the original color, drag the swatch onto the New Swatch icon to duplicate it before using this replacement method.)