My hair keeps turning purple everytime i dye it golden brown over blonde. Why?

Hi everyone. I have an issue with my haircolor turning purple when i put brown hair dye over my bleached hair. Maybe someone can help me out here?
So one day i decided to darken my roots, do this kind of balayage effect, light golden brown to blonde. I picked up some ion 6g and 6n at sally's , mixed it with 20vl (i had some regrowth) and put it over my roots. Let it develop for 20 min, washed it out and oh god. Most of it was brown but the closer it got to the mid-shaft the more purple it was. Why purple? I put gold on gold basically, i didn't use any ash. I decided to go over it with just 6g. Same issue, it got even more purple. I went ahead and made a second trip to sally's. Told the lady what happened and she told me to get 5g and try again. I did and it got darker obviously and so did my purple. I decided to strip the color completely and start fresh. Made a third trip to sally"s, picked up colorfix, 6g in a different brand AND a colorful warm brown filler. Girls that worked there didn't really know how to help me. I got rid of brown and purple, started out fresh. Put a warm brown filler on my roots, where i was planning to put the dye, waited 15 minutes and put 6g over the filler. Not only that my "balayage" turned out patchy and uneven, because it was harder to dye my roots over the filler, but i also got same result - purple. I got mad and stripped all the purple out of my hair. Now i have a very natural dark blonde transitioning into light blonde, but it is patchy in some places. Im not worried about the patchiness, i can fix it, but what color am i supposed to use in the future to avoid purple hair? Maybe i should have used a red filler instead of warm brown? Or maybe i should have used demi permanent dye instead of permanent? I don't understand how my hair turns purple if i put warm golden color on it? Ladies at Sallys don't know. Can't afford a professional right now, so maybe someone here knows a solution to this problem? Sallys girls offered me to try out light tagerine brown 5rg in demi permanent but im afraid it would turn my hair red. I have nothing against purple or red hair when people use those colors intentionally, but i personally wanted a natural look to my roots. Maybe i should try ash with red or warm brown filler next? Im going to leave my hair like that for awhile since it needs a break. But i am confused what to do with it in the future.