Weave hair CAN be colored if it is human hair. Synthetic weave hair can not be colored. This is why it is important to choose weaving hair that best matches your hair color. Although human hair weave can be colored, this is not an easy process.
Lightening hair weave
To lighten a hair weave color, you will need a color booster and bleach. We prefer Miss Clariol's hair bleaching agent. Mix the hair color, 40 volume developer, and bleaching agent carefully. Place the hair weave in tin foil and apply the mixed color. The colorizing will have been successfully completed anywhere from 10 minutes to 30 minutes depending upon the color. When you have achieved the color you want, wash the weaving hair THROUGHLY. And, condition it. Yes, you can and should condition weaving hair. Allow the a hair to air dry overnight. Then it is ready for use.
Darkening hair weave
To darken hair weave you will simply need a 20 volume developer and hair color. Mix these two together. Then apply to weave hair. I have found it best to apply dark colors to weave hair in a plastic bag. Allow the color to set until anticipated results are achieved. Most of the time, hair weave colors very quickly when you are attempting to darken it. Follow the steps above for washing, conditioning and drying hair weave after coloring.