SYNTAX

 var palette = Brewer.sequential(paletteName, numColors, minValue, maxValue)

 var palette = Brewer.divergent(paletteName, numColors, minValue, midpoint, maxValue)

 var palette = Brewer.qualitative(paletteName, numColors)

               -or-

 var palette = Brewer.qualitative(paletteName, ['list','with','every','category','name'])

​

 SEQUENTIAL PALETTE NAMES

 YlGn, YlGnBu, GnBu, BuGn, PuBuGn, PuBu, BuPu, RdPu, PuRd, OrRd, YlOrRd, YlOrBr,

 Purples, Blues, Greens, Oranges, Reds, Greys

​

 DIVERGENT PALETTE NAMES

 PuOr, BrBG, PRGn, PiYG, RdBu, RdGy, RdYlBu, Spectral, RdYlGn

​

 QUALITATIVE PALETTE NAMES

 Accent, Dark2, Paired, Pastel1, Pastel2, Set1, Set2, Set3

*/

​

function setup() {

    createCanvas(400, 200);

    background(220);

    noLoop()

}

​

function draw() {

    // on the left, draw a gradient with 9 shades drawn from the red sequential palette

    var pal = Brewer.sequential('Reds', 9, 0, 200) 

    for (var i=0; i<200; i++){

        noStroke()

        fill(pal.colorForValue(i))

        rect(0,i, width/2,i+1)

    }

​

    // on the right, draw a gradient with 'infinite' (i.e., interpolated) shades drawn from

    // the red-yellow-green divergent palette

    var pal2 = Brewer.divergent('RdYlGn', Infinity, 0, 66, 200) 

    for (var i=0; i<200; i++){

        noStroke()

        fill(pal2.colorForValue(i))

        rect(width/2,i, width,i+1)

    }

}