If you want the short answer, YES you can tone your HEC extensions with purple shampoo. If you’re looking at stepping out of bleach blonde/natural blonde shades and coming into creamy and platinum blonde, we recommend using Platinum Virgin Hair Clip-ins (#60) or Summer Blonde Virgin Hair Clip-ins (613) which are the lightest shades we provide. Start by filling a sink with water and a few pumps of purple shampoo, Mix them together, then place your Clip-in sets into water. Be sure to keep an eye on them until they are at your desired shade.
We know many of our customers use colour depositing shampoos/conditioners/products often and have success, we always recommend having a professional hair colourist who has had experience with extensions custom tone your HEC extensions using a professional toner.
Keep in mind that purple/blonde shampoos will balance out the golden and yellow undertones, natural and bleach blonde shades and make them much cooler and ashier. However, depending on your tone of blonde, this may not be the best alternative to making your extensions match better to your hair colour.
Since there are many different variations of cool-toned blonde shades, this is why we recommend having your hair extensions professionally toned at a salon that specialises with hair extensions.