I am red-green colorblind. how can i understand if i have deuteranomaly or protanomaly? is it possible to have both? is there a test for it?

Multiple ways: Red-blindness (protanopia) and red-weakness (protanomaly) and green-blindness (deuteranopia) or green-weak (deuteranomaly) are sorted out by your eye doctor with several tests: pseudoisochromatic plates (ishihara plates), anomaloscope; neitz-, nagel- or heidelberg multi-color-anomaloscope and the the farnsworth lantern and color arrangement test.

Yes: There is testing to figure out what to label your type of color deficit. Here is a link to a site that talks about different types which may be helpful to you. http://colorvisiontesting.com/color2.htm.

The farnworth test: Your eye doctor can run the farnsworth 100 to determine the type of color vision anomaly, but usually this would not change your ability to function or your long range prognosis or outcomes.

Testing is available: These types can be distinguished by proper testing. The most commonly used test, the Ishihara test, does not do this well. An older test, the HRR test is available in some offices to make this distinction. The 15 or 100 hue tests due this well. And there are laboratory test lanterns which can sort out all the subtle forms. You cannot have two forms of deficiency.