The yellow colour boosts the potency and energies invoked through Baglamukhi’s rituals and worship. It resonates with her intense nature and powers. Another interpretation indicates that Baglamukhi is really a corruption with the word Valgamukhi; valga signifies "bridle" or "little bit". Just like the bridle or little bit – https://www.youtube.com/watch?v=MtwXvn6T9ok