I saw a demo on youtube with nice light-blue rockets, grenades ands nails models. Does anyone know how to get those?
Thanks!

In lastest ezQuake (I think after qcon though, so you might need a nightly build), you can just do /gl_custom_X_color, to set the colour of rockets, grenades, lg & nails. /gl_custom_X_fullbright toggles the obvious.

Sounds like one of milton videos.
If so you could download his textures from his twitch channel, (And his config if you want)
https://www.twitch.tv/miltonizer
https://www.dropbox.com/s/xb1ji0db2hw4nbh/textures.zip?dl=0

If you use nquake you wont get it to look exactly like that since nquake use some custom grenades and nail models. Move/delete models.pk3. Or maybe just make a new install with id paks + ezquake install and miltons textures.