function contributorColor(contributorCount) {
  if (contributorCount > 2) {
    return 'brightgreen'
  } else if (contributorCount === 2) {
    return 'yellow'
  } else {
    return 'red'
  }
}
Determines the color used for a badge based on the contributor count.
The color varies from red to bright green as the contributor count increases.

@param {number} contributorCount Contributor count
@returns {string} Badge color