In my .emacs, I set "Source Code Pro" as my default font and solarized-dark as my default theme. But occasionally, I'd like to switch the theme and font in the current Emacs frame. After some Internet research, I find the commands to do this:

• to swith theme to solarized-light, do

M-x, load-theme, Enter, solarized-light

In Emacs 24+, one can also interactively set font using mouse by

M-x, mouse-set-font, and selecting font faimily, typeface, size in the Fonts pop-up window.

• to swith font, do

M-x, set-frame-font, Enter, Space (trigger auto-completition to look for candidates, and use Up, Down to switch font), Enter

References

• GNU Emacs manual, 22.16 Modifying Fontsets
• GNU Emacs manual, 22.15 Defining fontsets
• EmacsWiki, Font Sets