I'm often finding myself in need of parts which come in different colors in different
categories, however I would like an option to exclude multiple categories I'm
not interested in when using the Search function.
For instance, I'd like to be able to exclude Bionicle parts from a search for
lime bricks or plates in various sizes and thus narrow down the search parameters
a bit.
This could be handled very easily in the Category Summary, just have checkboxes
next to each category and the search results can be refined by clicking or toggling
a "display selected categories" box.
With the plethora of categories on BrickLink I find myself having to wade through
72 different categories just to search through lime colored parts and paring
these down by excluding undesired categories would be a great help!