Actually, when it comes to frock coats, you have a gender issue:cool:.
For gentlemen- yes, white breeches, and therefore yes, boots w/brown tops.
For ladies (I borrowed the writeup from Doug’s foxhunting in ol’ Virginnie web site):
Ladies wear a black frock coat or Melton coat with plain black buttons. A lady will wear a canary or tattersall waistcoat; a white shirt with a white stock tie and a horizontal gold pin; buff or tan britches of twill, cord, or leather; wash or brown leather gloves; and regular hunting spurs high on the heel. Boots will be of black calf without tops – tabs are sewn in but not sewn down. Ladies do not wear white breeches, or brown boot tops. With a Melton or a frock coat, ladies wear either a black velvet hunting cap or a black derby with hat cord.
PS If you are a field member as opposed to staff, that frock coat should have rounded skirt fronts, not square.