Why do some Hindu gods have blue faces?

The blue complexion or blue body is not considered symbolic or artistic.

It is considered by many hindus to be the actual appearance of some of the Gods, such as Krishna or Vishnu. There is not some complex reason for it, it simply is the appearance of that particular diety.

If that is not a satisfying explanation, consider a more esoteric one; It is said that the color blue is experienced in the upper portion of the head (the sahasrar region) of the yogi at certain advanced stages of deep meditation.

It is said that the yogi experiences God in that place. The yogi's chosen form of God, the "ishta deva" form of God (Sanskrit işţadevatā ) then takes personified form for him and may eventually grant that fortunate yogi "God realization" or enlightenment".

Some links are posted below. Hopefully they will not serve to confuse this subject even more:

THE BLUE COLOR OF SOME GODS:

Vishnu has blue color because he represents the status quo maintaining semi voluntary force, that makes our life as flexible as water.