Why wont my hair dye right?

The reason why the Loreal Colour Rays didn't work was because it doesn't come with bleach #30 is pretty dark and the color just probably didn't show through it. The Splat does come with bleach though and that's why the color worked. The reason why the #42 didn't work was because the color is not dark enough to cover it. You cannot lighten dyed hair with dye. So the only way to cover dyed hair is to go darker.