I’ve figured it out. In Appearance –> Customize –> Additional CSS, add a line to change any of the variable colors in global-styles-inline-css (this CSS is included in the page head section). The CSS update will look like this in your additional CSS update:
body { –wp–preset–color–picton-blue:#cc248b; } replace #cc248b with whatever color you want.
The other theme variable colors you can change to meet your website’s needs are:
–wp–preset–color–black: #000000;
–wp–preset–color–cyan-bluish-gray: #abb8c3;
–wp–preset–color–white: #ffffff;
–wp–preset–color–pale-pink: #f78da7;
–wp–preset–color–vivid-red: #cf2e2e;
–wp–preset–color–luminous-vivid-orange: #ff6900;
–wp–preset–color–luminous-vivid-amber: #fcb900;
–wp–preset–color–light-green-cyan: #7bdcb5;
–wp–preset–color–vivid-green-cyan: #00d084;
–wp–preset–color–pale-cyan-blue: #8ed1fc;
–wp–preset–color–vivid-cyan-blue: #0693e3;
–wp–preset–color–vivid-purple: #9b51e0;
–wp–preset–color–background: #ffffff;
–wp–preset–color–foreground: #111111;
–wp–preset–color–primary: #272423;
–wp–preset–color–secondary: #f9f9f9;
–wp–preset–color–tertiary: #000000;
–wp–preset–color–text-link: #111111;
–wp–preset–color–body-text: #555555;
–wp–preset–color–meta: #777777;
–wp–preset–color–border-color: #111111;
–wp–preset–color–rich-black: #030101;
–wp–preset–color–root-beer: #2b0f07;
–wp–preset–color–ironside-grey: #666666;
–wp–preset–color–white-smoke: #f6f6f6;
–wp–preset–color–dune: #333333;
–wp–preset–color–color-light: #fefefe;
–wp–preset–color–color-dark: #010101;
–wp–preset–color–woodsmoke: #0e0c0c;
–wp–preset–color–deep-orange: #ea6733;
–wp–preset–color–eucalyptus: #3fe0b3;
–wp–preset–color–picton-blue: #259ee4;
–wp–preset–color–color-white: #ffffff;