Orange color is used in India as a symbol of fire and purity. It is also used along with Saffron color because both looks somewhat similar.
Saffron/orange, signifies renouncement from the material world and a way to ultimate liberation. It's about leaving the short term satisfactions behind for achieving the ultimate liberty.
It is something I feel aligns with the philosophy of Bitcoin and its low-time-preference nature. The idea of "sell your chair to buy bitcoin" is just another way of saying "adopt a low-time-preference lifestyle", which is somewhat similar to the "Sanyas" lifestyle of a Yogi. 