Thanks for asking the query,
As you have mentioned you have smoking
addiction this can result in reddish spots on gums and palate
Other reasons causing this can be vitamin deficiencies, improper oral hygiene
, allergic reactions by some food products, physical or chemical trauma by some food products.
I would suggest you to visit to Dentist
and get checkup done.
Avoid smoking for somedays and look for changes, avoid eating hot, spicy food and candy which is causing trauma to your mucosa.
Meanwhile maintain a good oral hygiene, use saline water gargles 3-4 times a day to give soothing effect, use antiseptic mouthwash gargles twice daily.
Hope this helps out.