This post refers to HoudahSpot 3. HoudahSpot 4 can show up to three tag colors for each file. It always displays them in much the same way as Finder.
By default, HoudahSpot’s list view matches the Finder’s way of displaying file label colors. I.e. it uses a colored dot next to the file name on Mavericks. On older versions of Mac OS X, it colors the background of the row in the list.
A hidden preference lets you revert to the old style or use the new style on older versions of Mac OS X.