Colour Oops is a product that often produces more Oops than cries of joy. I don't know whether the instructions mention that after you use the product, any colour you decide to use has to be 2 -3 shades lighter because the hair will go much darker than intended. This is something to do with remaining chemical pigment in the hair not being thoroughly removed and affecting the next colour applied. It has happened to many people, so don't worry.
If you want to have another go at going lighter then I suggest you take a strand test and use the product again and see what results you get. After choose a shade much lighter than you want but in the same tonal family (golden,ash,copper etc) and see what the result is on the strand.
Failing that go have a talk with a colourist and see what they think, remember to give them as much information as possible of what has happened and what you ideally would like to be done.
