Thanks for your query, i have gone through your query. The pigmentation of the on the gums or the oral mucosa could be because of the antimalarial drugs particularly chloroquine. usually the pigmentation decreases gradually once you stop these drugs.if there is any increase in the pigmentation of the gums or mucosa consult a oral physician and get it biopsied. the bleeding or blood stained saliva could be because of gum infection which is usually associated with bleeding gums. get your teeth cleaned once and maintain oral hygiene after that by brushing your teeth twice daily.
i hope my answer will help you. take care.

hello thanks for consulting at hcm..firstly antimalarial do cause pigmentation of oral mucosa, gums and palate,, for how long did you take antimalaria drugs,, even generally some patients have black pigmentation on their gums bcz of increased melanin deposition which is normal,,but the bloody spit could be due to gingivitis-inflammation of gums,,so you require consultation with a periodontist for a check up and treatment,,you have to take iopa radiograph to check for alveolar bone levels,, then undergo oral prophylaxis-scaling and polishing,,also gum massage by pulp of the finger..do salt water gargle,,for the pigmentation at the gum line if it is due to antimalaria drugs--it is reversible, once you stop the drug ..once the drug is completely metabolized by your body,,and then physiological pigmentation could be treated by depeeling procedure,,so do consult a periodontist for the same,,hope it helps,,take care,,