i once ot mine red, and i´m thinking in getting blue/purple/hot pink highlights soon, i´ve only used permanent colors but i´ve seen some that last less washes, like 2-3, 5-6, 8-something and are called temporals or something or semipermanents but it also depends on your hair color.

i had very light hair when i got red, dark red, and it washed off very fast but i still had a washed out red for a long long time till it finally came off, thats why i want just colred hightlights