Is it permissible for a woman to wear colored lenses?
All Perfect Praise is due to Allah, The Lord of The Worlds.
Wearing colored lenses for treatment is permissible, and wearing them as an adornment is also permissible, provided that she isn`t seen while having them on by non-Mahrams (Marriageable men). And Alalh Knows Best.
Is it permissible for the father to give the Zakat of his money to his poor married son?
It is permissible for the father to give part of the Zakat to his poor son, if the latter was sound and healthy, because in this case the father isn't obliged to spend on his young son, even though; he is considered one of the Muslims poor. And Allah Knows Best.
Is permissible to buy/sell with non-Muslim?
Yes buying/selling for a Muslim with non-Muslim is permissible as regards what is lawful.
A man married a woman at the Islamic Centre in Brussels through a regular marriage contract. However, the husband left her for two years now and never provided her with financial support. Currently, she is staying in Amman, Jordan, and wants to remarry. Is her first marriage considered void and what should she do to remarry lawfully?
All perfect praise be to Allah, the Lord of the Worlds; may His blessings and peace be upon our Prophet Mohammad and upon all his family and companions.
This issue is within the jurisdiction of the Islamic courts and they have the final say regarding the dissolution of the first marriage contract if there is valid ground for that. Therefore, her first marriage remains valid unless a court decision says otherwise. And Allah The Almighty Knows Best.