An array of arrays of hexadecimal color strings from the “OrRd” sequential color scheme. The kth element of this array contains
the color scheme of size k; for example, d3.schemeOrRd[9] contains an array of nine strings representing the nine colors of the
orange-red sequential color scheme. Sequential, multi-hue color schemes support a size k ranging from 3 to 9.
An array of arrays of hexadecimal color strings from the “OrRd” sequential color scheme. The kth element of this array contains the color scheme of size k; for example, d3.schemeOrRd[9] contains an array of nine strings representing the nine colors of the orange-red sequential color scheme. Sequential, multi-hue color schemes support a size k ranging from 3 to 9.