The inner part of my feet were very very dark for years until recently i've been using pumice & cream for months. before the pumice it was very bumpy & rough. they're a lot lighter & smoother now...but why were they like that? and how do i make the scali

Callous: you had callous built up on your feet. Continue to make the pumice and cream a part of your routine and you will keep it from coming back.

Rough and dark: Without seeing your feet , a definitive diagnosis is not possible. However , your description sounds a lot like a candidal infection . See your podiatrist for further treatment .

Dark skin on foot: could have been dead skin that becomes dark with dirt or it could have been a fungus type of skin issue, either way if removing it and creaming helps, then continue to do so. Maintain good level of hygiene and wear clean socks and good breathable shoes on a daily basis. If the skin stays scaly, seek a podiatrist and a medicated topical will be recommended.

Try Urea cream: If you find yourself using a pumice stone all the time then get a prescription for urea cream. This should help as a long-term solution.