can you dye human hair extensions?

does anyone know if you can dye human hair extensions.. i had blonde hair and just dyed it bright red, i went to buy red extensions but they didnt have them in the lenght i wanted so im thinking of buying blonde ones and dying them with the same color i did my hair...  would it work? im not looking for an exact match of my hair color but just close enough at least hope they do dye.

You can dye extension hair, but a good working knowledge of color theory is mandatory if you want predictable results. 

It is not recommended that you lighten extension hair, but deposting pigment if fine.  Use a demi permanent color for best results, no ammonia and low peroxide.

And of course if you are making the color more than 2 levels darker, don't forget to replace the missing undertone, or you might end up with ashy-green, muddy results. 

Always do a strand test. 

Good luck!

thank you, i will be dying blonde extensions with manic panic which is semi permanant. thank you all.