Changing frame color on student in seating plan

Hi - can't find how to do this anywhere...Add a color to each student's frame. My understanding is that I could have a different frame color for students based on whether they have an entry in a column - some of my pupils have a blank column for a field, others have a Y and I'd like to have the Y pupils have a different color frame. Can anyone help?
Thanks
Fuzza

Tap and hold on a cell > Brush to change its color or tap and hold on a student to change the whole row.
You will usually find all the additional options with a tap and hold (on a column,header ,cell, tab, student, etc.)

Thanks - I see how to do it now. I thought it could be done automatically based on whether a column was blank or not for a student. I'm not keen on how there is the information added in a circle next to the photo of the student. I feel a subtle color difference to show if a pupil meets a single criterion or not is more discreet.
Fuzza

I missed the 'seating plan' part.
By default, the colours you assign to a student in a plan will not affect the other plans in the same class.
If you'd like to show that same frame colour in the grade book and all the plans at once, enable this option here.
iDoceo settings (main screen, gear icon top bar) > Seating plan > Frame color is linked to grade book