The Color format modifies the foreground and background colors of the object. Almost all objects support foreground and background color, the only exception are Data Items that use the Status Text, Status Image, or Bitmap style).
You can change the color settings with the following dialog box:
To set the foreground color you use the upper drop down box, to select the background color you use the lower one. The only special 'color' is Transparent. This means that nothing is drawn. This typically only makes sense for graphical objects and only for the background color. In this case the background is not erased and you can stack multiple objects on top of each other. The refresh of one will not erase the other.
Stripchart objects can display multiple graphs and you can set the color of each graph independently. If you select the Color dialog with one or multiple stripchart displays selected you will get the following dialog box:
The color for Graph 0 is equivalent to the foreground color. If you convert a stripchart display to a different type you will lose the settings for the colors of graphs 1 to 4.