It may be difficult to get your natural color. Blue doesn't have any red or gold undertones. You need those to get a natural light brown.
First condition your hair, using a good quality protein conditioner to even out the porosity. You can try applying a golden blonde tint to fill in the warm tones and then condition and apply the color that you want (the best way)
or just use a tint that is warmer (more gold) than the color you want to end up with. (Then pray <img src="/images/graemlins/smile.gif" alt="" /> )
You didn't say how long your hair is. If it is long,- past chin length - the ends may still appear muddy or grayish.