Hi Jerry,
Glad to hear you're enjoying Jutoh.
I think the problem is that you have a background colour in either your character formatting or your paragraph formatting, and this is overriding the table background. You should be able to tell where it is by showing the Styles tab in the Formatting Palette, clicking in the table, and looking at the information at the bottom of the Styles tab.
If using direct formatting, you may see something like Current + Background for the character or paragraph formatting. Or it may be enabled in a named style. If it's direct formatting, you can use Format | Character or Format | Paragraph to edit the formatting and disable the background; otherwise you will need to right-click over the style in the Styles tab and edit the style formatting. I always recommend using named styles wherever possible, although it's not necessary for e.g. a few characters of bold or italic.
I hope that helps.
Regards,
Julian