Is there any background to this depiction of the Imperial Crest on Empire Day?

I know, this can be a delicate question to ask and easily to get wrong, but I'm not asking for political statements and don't want to hurt someones feelings in that regard, so please don't digress.

In episode 6 of Star Wars Rebels season 1 called Empire Day, I noticed the Imperial Crest being displayed like a flag with black-white-red coloring in a few scenes of the episode, which – from my background – bears some resemblance to what many german citizens consider absolutely forbidden. I saw all currently released movies, watched Clone Wars as well as The Clone Wars, read a few issues of related magazines and played a few games set in this era (Empire at War, Jedi Knight 2 and 3), but I cannot remember the crest being displayed on a particular color – other than black, white, grey or no background – like shown below.

Is it just me? Have I overlooked something in the media listed above? Has the crest been depicted like this in other media previously?

I'd like to see a good explanation in-universe (Is there a special meaning? Is this releated to a certain era during the reign of the Galactic Empire? Is related to special occasions like Empire Day?) and out-of-universe (Is there any production background? Please don't just blame Disney.)

Also note the last sentence in the Empire Day Wikia article:

The term Empire Day was derived from a holiday within the United Kingdom celebrating the anniversary of the British Empire's formation between 1902 and 1958. Coincidentally, the holiday fell on May 20, which was also the day of the UK's premiere of Star Wars Episode V: The Empire Strikes Back, resulting in a "revival" of sorts.

As well as the section above about Empire Day in Star Wars Galaxies, which I haven't played and which was shut down on December 15 in 2011. Was there similar content in the game?

I'm not particularly schocked, because that's hard after finding Gundam merchandise like Zeon cleaning cloth for glasses, but that's another topic. I'd just like to have more background information on how and why.