The ps-slides Style

This style causes to produce output that can be printed on the QMS color printer with aptex to produce color transparencies. When the output is printed on a black-and-white PostScript printer, colors are printed as different shades of gray.

The ps-slides style has the following differences from the ordinary slides style.

• The \colors command is made a no-op. Colors that are not predefined must be defined with the \newpscolor command (see below).

• The \colorslides and \blackandwhite commands are the same, except that \colorslides prints only slides and overlays, not notes.

• The meaning of the \invisible declaration has been changed, as described below. The old \visible command is the same as the new \white command.

• The default page style is plain. (The alignment marks are no longer of any use.)

• The positioning of the body of the slide and the slide number have been changed to accomodate the QMS printer's small effective page size.

The new commands defined by the ps-slides style are listed below.

	\newpscolor{cmd} {red}{green}{blue}
	\renewpscolor{cmd}{red} {green}{blue}

Define the command cmd to produce a new color with the indicated RGB values, where red, green, and blue are decimal numbers between 0 and 1 (inclusive). For example:

	Black	$=$ [red:	0	, green:	0	, blue:	0	]
	White	$=$ [red:	1	, green:	1	, blue:	1	]
	Red	$=$ [red:	1	, green:	0	, blue:	0	]
	Light yellow	$=$ [red:	.5	, green:	.5	, blue:	0	]

For \newpscolor, cmd must not already be defined; for \renewpscolor, it must already be defined (but not necessarily as a color).

The following colors are predefined:

\black, \red, \green, \blue, \yellow, \magenta, \cyan, \white 

For ordinary printers, which assume white paper, \white text is invisible. Unlike in ordinary , color-changing commands can be used in math mode.

	\invisible
	\visible

Ordinary declarations of visibility of the text. Invisible text is not printed. (TEX prints it in a font that whose letters are all print as spaces.) Visibility is independent of color, so you can have invisible red text, visible green text, and even visible white text. (Visible white text can be seen only when printed by a weird printer that prints on nonwhite paper.)

	\norestore
	\restore

The \norestore declaration inhibits the proper scoping of color declarations, causing color declarations to act as if they were global. The \restore declaration causes the current and future colors to become the ones they would have been had there been no \norestore command. Both \norestore and \restore are global declarations. Example:

    \black black {\green green 
                         \norestore {\red red} red
                         \restore 
                         green} 
           black

The \norestore declaration is handy for color commands inside a tabbing or tabular environment. However, there are some anomalies:

• A \restore command inside a tabbing environment may not work exactly as it should. Try putting the command immediately after a \=, \\, or \>.

• An \fbox, \framebox, or \frame command may do weird things in the scope of a \norestore if there's a color declaration in its argument.

• A \background may behave strangely inside the scope of a
  \norestore.

\background{color}{text}

Typesets text in an with a box behind it whose color is determined by the color color-changing command. The yellow box is the width of text plus a border of width \bgborder around it.

	\hollowbackground
	\filledbackground

A \hollowbackground declaration causes any \background command in its scope to produce an outline, much like \fbox, instead of a filled box. This is useful for checking the slides with Proof or on a black-and-white printer. A \filledbackground declaration has the opposite effect.

\nogray

A declaration that makes every color other than \white be equivalent to \black, and issues a \hollowbackground declaration. Used to print the slides on a black-and-white printer so colors come out black instead of various shades of gray.