Scholarships for mathematics international students I'm from Colombia and I'm ending my undergraduate in mathematics and my GPA is 3.3/4; I only know Fulbright scholarships and the scholarships that offer DAAD, my favorite fields are PDE's and Analysis. What other complete scholarships are you know? Is possible to win something with my GPA? Sorry for the weird ask but I don't know another place to ask this question.
Your best bet would simply be to apply and hopefully get accepted to a PhD program somewhere like the U.S or in Europe. PhD programs in math, or in STEM in general, almost always guarantee funding which is free tuition + research/teaching assistantships which give some salary. 

Once you are enrolled in a PhD program and impress in your 1st/2nd year, then a lot more opportunities open up ranging from grant funding from professors to prestigious scholarships from big companies like Facebook or Google . Note that these programs are extremely competitive like top 1% of top 1% PhD students are accepted. That's why I am encouraging you to get accepted at a PhD program first.

I am also an international graduate student and when I was applying to PhD programs in the U.S, virtually all programs in the top 75 range had guaranteed support in the form I mentioned above. Even Fulbright would be more competitive from what I heard from its recipients.