AX Retail POS - change font type and font size of item grid and "Total" + "Tax" + "Balance" text

Hello, 
I haven't been able to find anything definitive going through the POS Services projects that would allow me to change the font type and font size on the main POS screen.

Here is an illustration of what I'd like to accomplish: Change the font type and font size of the items as pointed by the red arrows.

QUESTIONS:

• Can this only be done via DevExpress?
• If this can be done from code behind ... which Project and class should I be going to do the modifications?

Thanks