Coloring my Hair (Revlon Colorsilk Beautiful Color No.50 Light Ash Brown)

I want to have a lighter hair color. I have no idea what shade am I going to buy to get the right brown color for my hair. The last time I dyed my hair was November 2011 and i think that was also the last time i had my hair cut (just below my shoulder). I used Revlon Colorsilk Luminista No. 145 Burgundy Brown and i was happy with the result. My hair was so soft and no drying was observed. After a year, the color faded (of course) but it didn't leave a rusty color.

So after two years, I wanted to color my hair again. The Revlon mall assistant (the sales lady) gave me two options: Revlon Colorsilk Luminista No. 175 Medium Blonde and Revlon Colorsilk Beautiful Color No.50 Light Ash Brown. The term 'blonde' scared me so i chose the second one. I have a very long hair so I bought two boxes of hair color (Price Php395 each).

Since I have a dark hair, the color is not really obvious in pictures unless there is a strong presence of light. Also, the color is more of a dark brown. Actually, I did not follow one instruction (25 minutes total time) instead, I consumed a total time of 75 minutes (20-25 minutes application and 50-55 minutes soaking).