The cramps are likely because you are suffering from a condition called dysmenorrhea which is quite common. The uterine contractions are more severe than normal. Causes can be hormonal
or even alcohol consumption. A NSAID
drug such as Mefenemic acid 500mg once or twice during menses will help you.
Regarding the orange blood as long as it doesnt have a foul smell( indicating infection) there is no need to worry. Its most probably due to admixture of vaginal blood with vaginal mucous secretions.