thanks for sharing your concern
it is good to know that you have quit smoking
do not worry. your palate shows signs of inflammation. that is why there is redness.
some times a specific lesion of the hard palate
called STOMATITIS NICOTINA
is seen in smokers. The red spot represents dilated and partially occluded orifices(opening) of accessory palatal salivary gland
this inflammation is caused around the accessory palatal salivay gland duct.
on discontinuation of the habbit this should go.
observe for any associated changes. if so report to the dentist
else you can wait and watch for few more weeks.
meanwhile you can take capsule becasoules 01 OD for fifteen days.
do use mouthwash daily, hexidine 2% for fifteen days.
take nutritious diet and remain stress free.