Hi and thanks for the query,
Do not worry. Soft palate is darker than the hard palate
. It is even more dark in people who consume alcohol regularly. Colour of the soft palate can wary a lot depending on your race and even haemoglobin
. Do not keep looking at it since the dark colour is not significant.
If you are not having any symptoms related to tonsils like pain, soreness then you can just forget about it. Size of the tonsils does not matter if they are not causing symptoms.
So, rest easy,.. nothing to worry.