If I live and work in Washington for a California based company do I pay CA state income tax?

You pay income tax on earnings to the state where you earn it. That is California and will shortly become Washington (where state income tax is zero.) If you had any California source income, from rentals for example, you would pay California tax on that.

If CA decides to treat this the way that NY does, you will still pay CA state income taxes. In NY, if the move is strictly for the convenience of the employee, state income taxes are still due.

In general though you won't pay CA income taxes if you live and work outside of CA, regardless of where your employer is based.

your tax home is where you work, except for short, temporary, less than a year's duration

assuming this is self employment you will file a 540 NR on your Calif. income and the amount of time you are actually in Calif. will have an impact on the amount of taxes you pay

My husband was a long haul driver...company based in Arkansas. But we lived in WA and he never was even in AR. He had to pay AR state taxes.

You can ask the payroll dept of the company