Brian,

I think what I was looking for is:

            Infragistics.Win.Appearance activeItemAppearance = new Infragistics.Win.Appearance();

            activeItemAppearance.BackColor = System.Drawing.Color.FromArgb(192, 255, 192);

            ultraExplorerBar1.ItemSettings.AppearancesSmall.ActiveAppearance = activeItemAppearance;

1984 said:

Does the item support attaching a small image so the user can identify which one was last clicked? If not, what other control might help me with that?

Yes; the Infragistics.Win.Appearance object, which is the type of the CheckedAppearance property, exposes an Image property. The UltraExplorerBar.ImageSizeSmall/ImageSizeLarge properties provide a way to specify the size of the images displayed (one size, however, applies to all items).

1984 said:

It would be most useful if he could look at the UltraExplorerBar (or an alternative control) to know for sure where he is.

Just using the StateButton item style alone will accomplish this since the checked item has by default a different appearance than the unchecked items.

Does the item support attaching a small image so the user can identify which one was last clicked? If not, what other control might help me with that?

There are 5 items in the first group in the UltraExplorerBar. When the user clicks one of those items, his attention goes elsewhere on the main window. It would be most useful if he could look at the UltraExplorerBar (or an alternative control) to know for sure where he is.

Thanks, Lars