Oooh, di naman pala malayo yung color eh.
No need to bleach! Just pick a shade lighter than your desired haircolor para magshow up talaga. Bubble hairdyes aren't as good as what people expect, yan yung ginamit ko the first time. Haha.
Bear in mind that after coloring hindi halatang halata yung color ng hair mo, after a week or so, especially if everyday ka nagsh-shampoo, chka lalabas yung magandang kulay.
No idea with highlights, and I don't think it's advisable to diy with highlights. :/ Haven't tried tho.
I'm no pro in coloring hair, I'm just equipped with two years of recoloring/experimenting with haircolors.
I usually color my hair when bored, I've gone from my natural hair color-jet black to brown then brown with ugly dark blonde ombre then red brown then red then redbrown with blonde ombre. Haha!