Well i know that too much makeup does not look good with hijab. But i want to know is it not allowed to put makeup to look clean and fresh . And why is it not allowed since there was no makeup during rasool time. Also Kohl is makeup and why that is allowed. What if a person has bad skin and need to put some makeup to look normal.

Answer 

All praise be to Allah, and may his peace and blessings be on the last and best prophet and messenger, Muhammad.

With regards to kohl and similarly light makeup, there is some controversy, while some consider it from the ornament of the woman that may be shown (azzeenah azzahirah), others considered it not of it. It may be acceptable for a woman, particularly a single one seeking a partner to wear eye liner. It is however necessary for the woman to avoid tempting men, and if she felt she would be tempting, then she must avoid this act.
I advise the Muslim woman who is keen to please Allah to stay clear from the controversy and avoid the use of all forms of make up unless in front of women, her husband and/or mahrams. The single woman who is seeking a husband may however be entitled to some leniency here based on the hadeeth of Subay’ah, in which it is indicated that she wore kohl and went out of her home, which was taken as a sign that she was readying herself for accepting proposals from willing suitors.
If the skin is abnormal as you hinted in the question, then I hope that some use of light powder to cover it up may be permissible.

Allah knows best.