Webelos colors are an optional Webelos Scout uniform item whose use is determined at the Pack level. It consists of woven green, red, and gold streamers (tabs) on a blue metal bar with the border and word "Webelos" in gold. It is worn on the right sleeve immediately below and touching the U.S. flag if no Den number is worn (i.e. it covers the Den and Quality Unit insignia). If Den number is worn, under and touching the Den number. If colors are worn, activity badges are worn on the tabs.
In the late 1980's, BSA National moved to eliminate the Webelos Colors. This brought about a wave of 'static' from the field that resulted in it's continuation. The lingering effect of this action can be seen in the lack of documentation regarding the 'colors.' While it's proper display is very briefly illustrated in the 1997 - 1999 Insignia Guide, it is not mentioned in the Webelos Scout Book.
See Randy L. Worcester's historical reference to the Webelos colors in his "BSA History & Traditions" pages.