green yellow discharge is suggestive of an infection with trichomonas vaginalis
a sexually transmitted organism.
It can be easily diagnosed by examination of the discharge for presence of the organism. If it is positive a simple drug 'metronidazole' will cure your symptoms.
I would also advise you to wash the undergarments with hot water, change them regularly and treat your partner. Use of condoms helps to prevent spread.
Hope this was helpful.
Have a good day.