Mathematica allows full control of fonts, not only in ordinary text but also in typeset structures, graphics, and user interface elements. All features of fonts can be accessed programmatically, using symbolic specifications.
Style — create output with styling options
FontColor — color of text
Background — color of background
FontSize — font size in absolute points, or relative to overall image size
Magnification — overall magnification factor
FontFamily — , , etc.
Option Inspector — set any option for a selection, cell, etc.