Google script to add colours & focus time to your calendar

CalendarColor.gs

function ColorEvents() {
  const today = new Date();
  const later = new Date();
  later.setDate(later.getDate() + 20);
  Logger.log(`Updating from ${today} to ${later}`);

  const calendar = CalendarApp.getCalendarById('[email protected]');
  const allEvents = calendar.getEvents(today, later).filter((event) => !event.isAllDayEvent());

  function setEventColor(event, color) {
    const title = event.getTitle();

    // Do not override unless the color isn't the expected one otherwise
    // we can hit the API rate limit for modifying events.
    if (event.getColor() !== color) {
      const colorName = Object.keys(CalendarApp.EventColor).find(key => CalendarApp.EventColor[key] === color);
      Logger.log(`Updating ${title} to ${colorName}`);
      event.setColor(color);
    }
  }

  function ceilToNext15Min(from) {
    const date = new Date(from.getTime());
    const minutes = date.getMinutes();
    const minutesToTarget = Math.ceil(minutes / 15) * 15;
    
    date.setMinutes(minutesToTarget);
    date.setSeconds(0);
    date.setMilliseconds(0);
    
    return date;
  }

  // Color events
  allEvents.forEach((event) => {
    const title = event.getTitle();

    if (title.includes('Interview') || title.startsWith('Remote F2F') || title.startsWith('Debrief') || title.includes('Hiring Committee') || title.includes('Pre-Huddle')|| title.includes('Scorecard')) {
      setEventColor(event, CalendarApp.EventColor.PALE_RED);
    } else if (title.includes('1:1') || title.includes('1-1') || title.includes('/ Simon') || title.includes('Simon /')) {
      setEventColor(event, CalendarApp.EventColor.PALE_GREEN);
    } else if (title.startsWith('Flight:') || title.startsWith('Stay:')) {
      setEventColor(event, CalendarApp.EventColor.ORANGE);
    } else if (title.startsWith('OKR')) {
      setEventColor(event, CalendarApp.EventColor.YELLOW);
    }
  });

  // Create scorecard blocks after interviews
  allEvents
    .filter((event) => {
      const title = event.getTitle();
      if (title.includes('Interview') || title.startsWith('Remote F2F')) {
        return true;
      }

      return false;
    })
    .forEach((event) => {
      const nextBlockStartTime = ceilToNext15Min(event.getEndTime())
      const nextBlockEndTime = new Date(nextBlockStartTime.getTime() + (30 * 60 * 1000));
      const nextEvents = calendar.getEvents(nextBlockStartTime, nextBlockEndTime);

      const hasScorecard = nextEvents.some((event) => event.getTitle() === 'Scorecard');
      if (!hasScorecard) {
        const scorecardEvent = calendar.createEvent('Scorecard', nextBlockStartTime, nextBlockEndTime);
        setEventColor(scorecardEvent, CalendarApp.EventColor.PALE_RED);
      }
    });
}

For Google Scripts: https://script.google.com/

Create a new project. Add a file.

Then set a trigger on any Google calendar update