Could you put blue highlights in black hair without bleaching it?

Yes you could. One of the cheapest way is to get a colour tube - they are available in lots of hair saloon. It works like a mascara, just pick the colours you want and swipe it on. I've done this for my friend's daughter who for one of her nights out. It was blue too. It looks lovely and you just have to wash it off. Hope this helps.

Could you put blue highlights in black hair without bleaching it?

no, my hair is black too and the color wont show up unless you bleach it first.

Could you put blue highlights in black hair without bleaching it?

yes you can, but having black hair, it wont show much, however, what you can do is buy purple hair extensions. u can buy these in watson, shu eumura, or any wig shop. its great, u dont have the hassle of highlighting your hair. clip on the extensions and you're ready to go.