1) How to Change Countdown Font Color?

Write this custom CSS in WordPress Appearance = > Customize (see additional CSS)

Then replace the current color code with your own color one by one

.countdown-layout2 .countdown-section:nth-child(1n) h2 {
  color: #fad03b;
}
.countdown-layout2 .countdown-section:nth-child(2n) h2 {
  color: #00b0ff;
}
.countdown-layout2 .countdown-section:nth-child(3n) h2 {
  color: #f50057;
}
.countdown-layout2 .countdown-section:nth-child(4n) h2 {
  color: #fad03b;
}

2) How to Change Event Time Format?

You can change Time Format from Theme Option.

Go to Theme Option => Layout Defaults => Event Archive (see bottom)

Event-time-format