Reference/BGFont
From NSIS Wiki
BGFont
[font_face [height [weight] [/ITALIC] [/UNDERLINE] [/STRIKE]]]
Specifies the font used to show the text on the background gradient. To set the color use BGGradient. If no parameters are specified, the default font will be used. The default font is bold and italic Times New Roman.
Command introduced with NSIS v2.01