Just me and DP in the house, and laundry is my job. I do:
Towels and DP's work shirts on a hot wash - Wednesday
Bedding on a hot wash - Saturday
Woollens on a wool wash - once every few weeks at this time of year, once a week in the winter
All other stuff in a 30 degree wash, unless it's a thing like new black jeans, which I would be more careful with - usually twice a week
I don't tend to separate by colour, just item type.