I've never seen a red light, but the UK has had multiple electricity rates for households since the 1980s.

https://en.wikipedia.org/wiki/Economy_7

My parents would set timers on the dishwasher, washing machine etc too run at night.

> My parents would set timers

I'd suggest first measuring how much single load uses. In my case it's 1KWh and 0.4KWh. Daily load would save perhaps 4-5 GBP per month or 5% off an average bill.