Font Style and size for axes labels

I am writing a code for plotting two graph lines on one plot with different Y-axes on either side for individual graph line. One of the axes I am plotting with the graph (first one) so it is taking the default font style and size from ROOT. And the other one I am manually designing and placing on right side of the graph plot. I want to know what are the default fonts and sizes that ROOT uses for Axes label and titles so I can make the manually design axes same as the first one.

For reference I am attaching the jpg file (level.jpg) of the plot I am talking about. I want o make both the Y axes look exactly same except for colour.

You should set the font Helvetica. Number 42