You can match most bands with any Apple Watch Series 3 or later case of the same size.
40mm, 41mm, and 42mm bands are all compatible with 40mm, 41mm, 42mm case sizes. 44mm, 45mm, 46mm, and 49mm bands are all compatible with 44mm, 45mm, 46mm, and 49mm case sizes.
The Solo Loop and Braided Solo Loop bands are only compatible with Apple Watch SE, Apple Watch Series 4 or later, and Apple Watch Ultra or later.
For Solo Loop and Braided Solo Loop, the 40mm, 41mm, and 42mm cases are compatible with band sizes 0-9; the 44mm, 45mm, 46mm, and 49mm cases are compatible with band sizes 0-12.