Initially I thought the cake will turn out to be either light blue or purplish colour but it ends up pale green which resemble matcha cake. Guess next round I have to intense the colour by adding more dried blue pea flowers while making the "blue water".
Blue Pea Flower (蝶豆花) also known as butterfly blue pea is a tropical vine growing around fence that bloom beautiful blue flowers. The petal is rich in vitamins A, C and E. According to some research and myth, drinks made using these dried petals can help to improve the immune system, beautify complexion as well as a natural collagen on itself.
Besides that you can also use the "blue colouring" (obtain by soaking a few dried petal in water) to make Thai or Malaysian cuisines like Blue Rice (nasi kerabu), Nyonya dumpling (with hint of blue rice), Khanom Chan (Thai dessert) and more.
BLUE PEA FLOWER CHIFFON CAKE