A woman in iddat

As Salaamu Alaikum respected mufti

My dad passed away on 04 Ramadaan this year. My mum is now in idaat. Few people are telling her that she should wear white clothing or light colour clothes etc and not black. They also say that after her idaat she must go and stay at some other family members house and they will buy new clothes etc for her

I personally find this absurd, if I am not wrong. Allah knows best.

Please advise on the validity of such practices

Shukran