Talk to General Physician on Cancer Medication Side Effects

Hi. Do we have a medical oncologist here? My father was diagnosed with colon cancer. He had an operation and now is under chemotherapy. His new reports have zero infection rate now. But still the doctor has suggested for 6 rounds of chemo. Anyhow he is given these meds to eat after the second round of chemo. CAPECITABINE. He is complaining of dark palms and feet soles. Kehre hain k literally black horahay hain unkay palms and feet soles. Please can anybody guide if this is the side effect? Will it go away after the chemo? Please help thanks