How do you test your hair extension samples?

[Gorgeouslocks21]

if I get samples that Are a similar colour to my hair I wear them to test them out. But don't know how to test for example the blonde shades that I can't wear and wash myself? Do you just wash them multiple times??
Thanks X

 

[courtjb91]

Wash, dry and straighten/curl again and again and again.

I also test with professional shampoos and shop bought