1000 is blue, 100 is violet

colors
When the Philippine New Generation Currency series was released in December 2010, it was intended for the 1000-peso bill to be light blue and the 100-peso bill to be violet. But the actual design of the 1000-peso bill (shown above at the top) had some violet portions and the 100-peso bill (shown above in the middle) had some blue portions.

This helped some tricksters make some easy money. They would show a cashier of a small shop a 1000-peso bill and ask for it to be exchanged with smaller denomination bills of equal total value. When it was time to exchange the bills, the tricksters would swap the 1000-peso bill with a 100-peso bill folded so that the blue portion was visible and the figure “100” was hidden.

To avoid confusion, the Central Bank of the Philippines changed the colors of the 100-peso bill starting with those dated 2015 A, changing most of the blue color to violet and lilac (as seen above at the bottom).