Hi virgilp, I believe they're charity labels sold to raise funds for orphans (huerfanos) of telegraph service workers.
I've checked my collection and this set seems to come with each stamp having two different background colours. I've got two different colours for each stamp apart from the lion and the camel stamps where mine have different colours to yours. I also have stamps from a set showing buildings and four from a set with flower designs.
Indeed, I saw this set in two different colors. But who issued it and when? I couldn't find any more info!
BTW, the two sets with different background colors are offered at Hipstamp by sellers: antonios nlarosa
