Look for "color payoff" and "bleeding." Some blues are notorious for staining pillowcases and towels!
If your hair isn't light enough, blue dye can turn green (blue + yellow = green). You may need to bleach or use a toner first. 3. Pro Tips for Buying buy blue hair color
If you have thick or long hair, always buy two boxes/bottles . Nothing is worse than running out halfway through. Look for "color payoff" and "bleeding
Necessary for pastels and bright cobalts. buy blue hair color
While you're at it, grab a color-depositing conditioner or a sulfate-free shampoo to keep that blue from turning dull.