The majority of jurists are of the view that a man’s thigh is `Awrah and it must be covered.

With regard to necklaces, it is not known that this custom is widely practiced among men without any objection; rather hardly anyone does it except effeminate men and their ilk, or those who imitate women or evildoers. So it is not permissible for you to wear it for that reason.

It is permissible to wear white, red, yellow, green, striped and other colours of clothing, and there was no difference of opinion concerning that, and none of them are makruh. It is also permissible for women to wear whatever colours they like, so long as they do not display themselves in front of non-mahram men.