AdvStringGrid and Win 10 Pro

Good afternoon to all,
with delphi 10.3 (and 10.4.1) and win 10 pro i have a strange behaviour with advstringgrid and fixedcolor.
I drop the grid in the form and it start with fixedcolor=clwhite and all grid is white.
If i change the fixedfont (i.e. color or size) the change is applied .... but if i change the color (fixedcolor) to any other color the fixed column and row still remain withe.
How can set a custom color ?
Sure i miss some setting .....

Thank's for reply
Regards
Daniele

Set grid.Look = glSoft / grid.UIStyle = tsCustom and then grid.FixedColor = yourcolor

Thank's Bruno.
With grid.Look i have enougth option ....
I missed this option...

Regards

Daniele