Hi i play on a c4 x75 server and i created a bladedancer and a sword muse..i want to add dyes ,to buff faster .. i should get wit or dex?because they are fighters and idont know if buffs are physical or magical sklls..what dyes should i get?

Dances and Songs are physical skills, their cast speed improves with attack speed, which means DEX will suit you better. Though the boost you will get from adding +5 DEX won't be as big as let's say... Haste SA on +4 dual Keshanberk*Keshanberk for example.