This file is from Wikimedia Commons and may be used by other projects.
The description on its file description page there is shown below.
The flag of Bulgaria. The colors are specified at http://www.government.bg/cgi-bin/e-cms/vis/vis.pl?s=001&p=0034&n=000005&g= as:
[[File:Flag of Bulgaria.svg|border|96x176px]]
Click on a date/time to view the file as it appeared at that time.
The following page links to this file: