"The Maltese tiger, or blue tiger, is a semi-hypothetical coloration morph of a tiger, reported mostly in the Fujian Province of China. It is said to have bluish fur with dark grey stripes. Most of the Maltese tigers reported have been of the South Chinese subspecies. The South Chinese tiger today is critically endangered, and the "blue" alleles may be wholly extinct. Blue tigers have also been reported in Korea, home of Siberian tigers.
The term "Maltese" comes from domestic cat terminology for blue fur, and refers to the slate grey coloration. Many cats with such colouration are present in Malta, which may have given rise to the use of the adjective in this context."
Wikipedia