One way you can use color palettes in a sketch

Color Palette example.pde

/*
Color Palette example sketch
Steve Lambert 2017-02-09
*/

// My Pallette
// Taken from https://color.adobe.com/Aspirin-C-color-theme-251864/edit/?copy=true

color darkBlue = color(34,83,120);
color medBlue = color(22,149,163);
color lightBlue = color(172,240,242);
color offWhite = color(243,255,226);
color orange = color(235,127,0);

// other variables
int circleWidth = 50;

void setup() {
    size(1000, 200);
    background(offWhite);
    noStroke();
}

void draw() {
    background(offWhite);
    fill(darkBlue);
    ellipse(width/5*4, height/2, circleWidth, circleWidth);
    fill(medBlue);
    ellipse(width/5*3, height/2, circleWidth, circleWidth);
    fill(lightBlue);
    ellipse(width/5*2, height/2, circleWidth, circleWidth);
    fill(orange);
    ellipse(width/5*1, height/2, circleWidth, circleWidth);

}