The -navigationType resource controls how the keyboard affects widgets navigation. Keyboard shortcuts are often used to quickly change input fields, as with the <Tab> key.
Simple bicolor drawing is done using the Primitive's foreground color over the Core's background color. Other colors default to mixing these two at widget creation time. When they are entered (gain the input focus), primitive objects are often highlighted by drawing a color border around them. They can also be enclosed by a beveled shadow frame, making them appear to be standing out or recessed (a 3D effect).
The -unitType resource selects screen-dependent, font-related, or device-independent units. It affects subsequent dimension resources for that widget only.