The blue ringed cover was the first issue to be released by EMI.  It's widely found in album format, however some CDs do exist.  In fact, if you have a blue ringed CD, consider yourself very lucky!  Only a few hundred of these exits and are quite valuable.  A few months after it's initial release, EMI canned the cover and went for the more widely accepted (and viewable) gold ring cover.
	EMI released the gold ring cover soon after.  It was initially thought that the blue ring concealed the title "QUEENSRYCHE" & "RAGE FOR ORDER".  And thus this new gold ring design became it's replacement.  Among the four covers, the gold ring is most widely distributed cover.
	While in Japan, the gray ringed cover was the cover choosen.
	The white ringed cover was only found on the US re-release of the cassette in the early 90's.  It is now out of print.