Closer, yes, and still not the English spelling. The Cantonese is gam gwat, golden orange, and the first syllable has an a vowel. Nineteenth century English writers wrote it several ways before settling; cumquat is still current in British and Australian use and puts a c on the front. But the form that reached the dictionaries has u in the first syllable and k at the start, and kamquat is not among the variants that survived.