Can you dye or bleach dreads? - Dreadlocks FAQ's
Yes, blonde dreads look amazing! Dying or bleaching the hair is easier before its dreaded and the dying and bleaching process will leave the hair a bit dryer and more fried which will make it dread faster. So if you plan to bleach or dye, do it before you dread if you can.
If you dye or bleach it after its dreaded wait till the hair is good and locked, about 10 to 12 weeks. Remove any remaining wax with a hair dryer so the color will stick. After you bleach or dye, do not use the conditioner that comes with the kit as it will harm your dreads. Don't over bleach it because the dreads can get dry and brittle and possibly break off. Dread breakage is almost always related to over bleaching or some other chemical process. After you bleach your dreads they will feel dry and tight, use a little wax to smooth them down and replace the nutrients.
I'm a big fan of keeping my dreads natural - My first set was natural except for the bleaching I did. I decided I didn't want to keep re-bleaching them and I started letting the bleached part grow out. It looked pretty funny. I kept my second set completely natural - no chemicals of any kind. Of course I started them with a DreadHead Dread Kit according to the DreadHead instructions and tips. After experiencing both, I myself prefer to not use bleach or dye, but you certainly can and you should have no problems if you use it responsibly. =]