'Brown' may be caused by a number of things. Most likely cause is iron in your water, which is very common.
from the water picking up brown sediment, i.e. dirt
Rain disturbes the silt at the bottom and causes it to rise in the water amking the murky-brown colour.
iron
Skidmarks account for 84.7% of all brown marks in a toilet bowl . Followed in a distant second place by Iron in your water.
Usually iron
See the related link on what causes brown discharge after period.
Possibly your hot water tank is rusting out on the inside and will need replacement soon.
If the plumbing in your house is old, it is probably rusty water pipes or rust from within the Hot Water heater. Des Perado
Can be iron or other sediment or tannin. If it persists take a sample for analysis and then you will know if and what kind of filter to get.
There is dirt entering the supply pipe. This is common when city repairs pipes in some areas.
"Butterscotch" oil means water in the oil - cracked head or bad head gasket
There can be a number of reasons for brown well water, some serious and some not. A lab test is necessary to define what it is. If you are drinking this water don't waste time, get a lab test asap.Your family's health may depend on it.