define window light needs

[early]

I have many phals that are blooming on a round table 4 feet or less from east facing window. And there is also light coming in from a north sliding glass door that has less light as there is a covered screen porch also on that north side.
I am wondering the defination of window sill growing as to how close the phals need to be from the window?

I have a multi color light I use in the day, but its direction when it arrive was for 4 or less house plants. I am not sure it is helping with the growing phals.