Can permament dye fade?
I dyed my hair with a non permament dye a long while ago,
it was brown before that, and when I dyed it again it turned black.
It started fading to brown once more, and my dark kinda dirty blonde hair started growing out
, so I bleached it light blonde with a permament dye.
and now my darker blonde hair has started growing out again,
I just want my old haircolour back, having it really dark blonde at the top and the rest
light blonde doesn't really look good.
What should I do?

If you want your natural color back, you will need to do a tint-back. A tint-back is when a stylist attempts to match your natural hair color. This process is really tricky to do yourself because your hair is porous, and if you use an at-home dark blonde permanent color, it will come out too dark or an unwanted shade. You should consider going to the salon and have it done. The hairstylist can mix a formula to match your natural color as close as possible.