Hello,
I have noticed blackish dots on the glans(head) of my penis before, but one became very prominent. If I "google" this type of mark I cannot seem to find anything. It does not resemble HPV or HSV - no pain no itching.
I am sexually active, safe sex always and unprotected receptive oral sex... I also notice the glans has red and white blotches on it through out the day - I am not sure if I am paying closer attention or I have something going on.
I have seen this colour variation before to what would normally be the things that are naturally present, only the colour is different to what is surrounding them.
I would suggest this is a natural variation - you would need to check with a Urologist if you wanted to be 100% sure.
In terms of the blotches is this you are noticing everyday or following having sex the previous night?
So you would get variation like this either based on the demands made of your penis, such as rough sex. as an example. Other things can be what the skin is in contact with. here condoms are an example of this, suspect if you have recently changed brand or type.
Then there is pretty much anything that the skin of the glans is in contact with. so this can be if you are applying anything like a soap or shower gel directly to the head and the skin is reacting to this.