HTC One was launched in Black and Silver colors back in March of this year. Later we saw Ruby Red exclusively with Sprint as well as Glamour Red in the UK. Besides, there was a Metallic Blue version for the U.S.
From the leaked pictures it seems that it is the outer shell of the HTC One. It is just the external casing and does not feature any electronic components. And if these recently leaked pictures are accurate, then we might be seeing a HTC One in gold coming soon from the manufacturer.
As the HTC One phone is quite popular in Europe and on all major US carriers, so the flagship device might be gladly welcome in more colors.