The "active" cell with the "focus" is dull green on gray. Its hard to pick out.
Even harder if you use the search function. Good luck seeing where on the screen that cell is.
Please allow us to change the outline of the selected cells or the cells that have the focus. Telling us to download a windows color theme really doesn't help - many of us are blocked from doing so - and a theme that is good at one thing is usually a complete failure at something else. Sometimes I really miss XP and the way it could be customized to fit your actual needs.
Mark Woodhead commented
I agree completely. An option to set the focus format would be very useful. It could be the cell outline or the background color - it could be different for each worksheet so that it is highlighted to the user and not lost amongst many cells.