function set( v ) {
	/* eslint-disable no-invalid-this */
	var isStr = isString( v );
	if ( !isStr && !isStringArray( v ) ) {
		throw new TypeError( format( 'invalid assignment. `%s` must be a string or an array of strings. Value: `%s`.', 'colors', v ) );
	}
	if ( isStr ) {
		if ( COLORS[ v ] === void 0 ) {
			v = [ v ];
		} else {
			v = COLORS[ v ].slice();
		}
	} else {
		v = v.slice();
	}
	debug( 'Current value: %s.', JSON.stringify( this._colors ) );

	this._colors = v;
	debug( 'New Value: %s.', JSON.stringify( this._colors ) );

	this.emit( 'change' );
}
Sets the data colors.

@private
@param {(string|StringArray)} v - data colors
@throws {TypeError} must be either a string or an array of strings
@returns {void}