On the Parser menu, you can select one of these too modes: Text Glossing or Parser Develpement. The use of background and border colors varies slightly in the two modes.
The Text Glossing mode prioritizes the user opinion when there is a choice of the color to display.
A white background indicates a user has approved the analysis in the current instance. A blue or tan background means there is a possible analysis that has not been approved by the user in the current instance. Possible analyses can come from a previous user approval, a parser approval, or an entry from the lexicon. Tan is used to indicate a successful multi-morphemic analysis by the parser.
The Parser Development mode prioritizes the parser opinion.
A blue box (with a white background) indicates that the user has approved the analysis, but the parser cannot validate it; a tan box (with white background) indicates that the analysis has been both validated by the parser and approved by the user; a tan background indicates that it has been validated by the parser, but the user's opinion is unknown. The absence of any special coloring indicates there are no candidate analyses from either the user or the parser.