My Experience With Dying Fabric

Story: I just posted saying I made a white White Of Space hood, and said I would dye it when I got the chance. Well I did not mention that I have already tried to dye it. I had lots of white fabric, and Black fabric dye, so I thought why not make it out of the stuff I have, so I don't have to buy anything. I finished sewing it a few days ago, and yesterday I went to dye it. Well, I get the dye already, and it kind of looks Dark Blue instead of Black. I think to myself that it will get better, so I throw in the hood, and it turns Dark Blue! I'm like great! This dye said it would be BLACK, but instead it is Dark Blue! I'm like if I let it sit it will become Black. 2 hours later! Still not Black. I call Jen and Jessica and tell them what is going on. Jessica was with a friend, and he said that I might have used Polyester Fabric, which wont dye with normal dye. I'm like great. I just wasted my time and fabric dye for no reason. Well I take it out of the bath of dye, and wash it off to see stays on a little bit, and just throw it into the washing machine. Guess what happened. IT WASHES IT ALL OFF!!! IT'S BACK TO BEING WHITE! I'm so pissed of at this point, that I just throw it in the washing machine and go to bad. I didn't even want to deal with it anymore. Well I went and bought some fabric dye for Polyester fabric, and spent $8 on it! Why is it so expansive? So yeah ... my story to figuring out not all fabric dyes the same way.