Removing pubic hair and armpit hair helps one to attain a perfect level of cleanliness and prevents what could emanate from them of bad smells if the hair was left without removing it.

It is makruh to pluck grey hair from the head or moustache because of the hadiths narrated from the Prophet (peace and blessings be upon him) concerning that. But if the grey hair is in the beard, it is haram to pluck it.

It is permissible to dye hair any colour apart from black, and there is no differentiation in this regard between old men and young men. So, it is halal to dye your hair red and yellow, but there are some guidelines to keep in mind, such as not imitating people who are evil and disbelievers. Please read below for details.