Can you veg with a light made for flowering?

My buddy gave me one of his big Sunburst CFL 125w with mini ballest and reflective housing thing as well.

My plants are currently in veg, if I introduce this light and put it in my normal 18 hour cycle will this light (being that its for flowering) cause my plants to flower?

No they will not go into flower until you switch to 12/12. The light will be fine.

he was just telling me that the color of the light was made for flowering, thus me thinking that. so the only thing that makes a plant flower is the 12/12?

Yes.
You can use the same light to veg and flower, all you do is change from 18/6 or 20/4 to 12/12 when yor plants are ready.

great thank you!