Whites to darks is how I was taught.
On the farm with my grandmother this was the sequence:
Wash water 1 - full hot (water heater was set at 145) no chance you could put your hands in this at the beginning.
1. Sheets: 10 min.
add bleach
2. men's underwear: 10 min.
3. light towels: 10-15 min.
4. lighter dirty workclothes: 15-20 min.
Wash water 2 - medium hot
1. Dress shirts & women's underwear: 8-10 min.
2. Light dresses, blouses and slacks: 10 min.
3. Dark dresses, blouses and slacks: 5-8 min.
4. Dark towels and lightly soiled dark workclothes: 10 min.
5. Heavily soiled dark workclothes: 20 min.
And yes, a washday for a family of 8 did require 9 or 10 loads
An additional 1/4 to 1/3 cup of Tide was added to each load to keep the suds up.
Fresh water got a whole cup for a Maytag E2L. Water was hard there, probably 15-20 grains.