in some parts of my body (mainly private parts) the skin color is very darker compared to the main skin color of my body, is it permissible to change it so it is the same as my normal skin color by bleaching or by other methods? (please note it was not like this before).

Praise be to
Allah.

 

Firstly:

There is nothing wrong with changing the
colour of the skin from dark to white, using creams,
cosmetic preparations and the like, if the change is temporary. But if it is
changing the colour of the skin permanently, then it
is not permissible, whether that is done by means of surgical procedures or
other means, because that is changing the creation of Allah, may He be exalted.

For more information on the ruling on
surgical procedures, please see the answer to question no. 1006

Shaykh Ibn ‘Uthaymeen (may Allah have
mercy on him) was asked: What is the ruling on whitening creams for the skin?
Is there anything wrong with using them for women?

He (may Allah have mercy on him)
replied: if the whitening is permanent, then it is not permissible, because
this is akin to tattooing and filing the teeth. But if it is whitening the face
for a specific length of time, and when it is washed it will disappear, then
there is nothing wrong with it.

End quote from Fataawa
Noor ‘ala ad-Darb

He was also asked: Recently there has
appeared medicine that makes a dark-skinned woman white; can she take it or is
taking such medicine haraam because it is regarded as
changing the creation?

He (may Allah have mercy on him)
replied: Yes, it is haraam if it changes the colour of the skin permanently. In that case it is like
tattooing, and the Prophet (blessings and peace of Allah be upon him) cursed
the woman who does tattoos and the woman who has tattoos done. But if it is
done to remove a defect, such as if there is a dark, disfiguring mole on the
skin and the individual uses something to remove it, then there is nothing
wrong with that.

End quote from Fataawa
Noor ‘ala ad-Darb

Secondly:

If the skin was originally white then it
turned darker for some reason or because of sickness and the like, then it does
not seem that there is anything wrong with using permissible creams and medicines
to restore the skin to its original colour. This is
not regarded as changing the creation of Allah, because it is removal of a
defect that has occurred and is not changing the original form.

For guidelines on what is meant by
changing the creation of Allah, please see the answer to question no. 129370

But we should point out that a man
should not be preoccupied with such matters or go to extremes in paying
attention to them, because it is a waste of time and money on something that
does not bring much benefit, and it may distract him from things that are more
important and more beneficial. It is not befitting for men to be preoccupied
with adornments and beautification; rather they should be focused on more
important matters.

Have you not heard what the poet said:

War and fighting have been decreed for
us and for young women it is decreed that they should wear beautiful garments.

And Allah knows best.