It has always been possible to color TeX output. To do so, add the line
to the preamble, and insert a line like
before typesetting begins. To color a limited section of text, use a command like
To define custom colors, use a command like
Users may be familiar with a list of defined colors with names like "BrickRed"; these named colors were defined automatically for the dvips driver. To use them generally, use the syntax
When output is colored, the output may be difficult to read on the preview screen. TeXShop has hidden preferences to set the background color of the preview window. This background color will not appear when the document is printed. To set the background to gray, issue the following commands in Terminal:
Change 0.5 to 1 to get back to white. If you find yourself changing the background often, create an Applescript macro named "PDF background gray" with the Macro Editor using the following text:
and create a similar macro named "PDF background white".