Good evening!
Just to clarify, are you to analyze illustrations of the story or different versions of the text throughout these time periods?
When we analyze a text, we are trying to look at it from a certain point of view. Psychoanalytic, constructionist, deconstructionist, and feminist are all examples of literary criticisms; there are numerous others out there. If your instructor wants to you pay attention to certain themes such as context or the importance of color, perhaps you should start off by seeing if there are any obvious connections there. Take the tale in all three instances and see if these things are consistent throughout each tale.
You could start your research by doing an internet search using keywords such as "the Arthurian legend" and "color" or "critical analysis". This should get you started with some ideas for further research. It may also help to choose a specific critical analysis and try to apply it to the text.
I hope this helps you get started.
Regards,
Gloria
Moderator, EssayForum.com
Gloria, EssayForum.com