MPH Tick Countdown

How would you change this indicator so it would plot the countdown in white instead of black?

const lodash = require("lodash");
const predef = require("./tools/predef");
const meta = require("./tools/meta");

// Counts down the number of ticks left in a bar on a tick chart 
// directly above the current bar"
class mphTickCounter {
map(d, i, history) {
    const coordinates = {};
    const cd = this.chartDescription
    if (cd.underlyingType == "Tick") {
        // The value must be different every tick, otherwise the chart will not update.
        // However, if the value is set to the number of ticks, the chart will attempt
        // to autofit to include the number of ticks even if the value is not shown,
        // so we set the value to something around the current price, and expect to never
        // display the value.
        
        const newValue = 
            d.value() === this.lastValue ? d.value() + this.contractInfo.tickSize : d.value()
        this.lastValue = d.value()

        const maxTicks = cd.elementSize
        const remainingTicks = maxTicks - d.ticks()
        const text = remainingTicks > 0 ? remainingTicks.toString() : ""

        return { 
            ticks: {
                text: ["", text],
                x: [d.timestamp(), d.timestamp()],
                y: [d.low(), d.high()],
            },
            value: newValue,
        };
    } else {
        return {};
    }

  }
}

module.exports = {
name: "mphTickCountdown",
title: "[mph] Tick Countdown",
description: "Tick Countdown",
tags: ["mph"],
calculator: mphTickCounter,
params: {},
inputType: meta.InputType.BARS,
plotter: predef.plotters.zigzag(["ticks"]),
scaler: predef.scalers.multiPath(["lower", "higher"])
};