alright, no need to be too harsh on the guy...
okay, as mentioned before, it's VTEC, not Vtech. When you're accelerating, and you hit 5k rpms, the engine switches over to VTEC ("mode" if you want to call it that), changing different aspects of the way the engine acts, and in the end giving you more power. It's normal for engines with VTEC to be noisier when it engages. How much noisier it gets all depends on some of the modifications that have been done to the car.
When you said the block is red, what you're looking at is the head, not the block. The head is attached to the top of the block. I think it's clear now that you have a VTEC head, but what's still up in the air is what engine you have...it could be the engine from an LS (engine w/o a VTEC head) with a replaced head that had VTEC, or it could be a true GSR engine, in which case it comes with a VTEC head. To find this out, as JDM:_Hotness said, look at the block. There should be a small metal plate that has the engine code on it. It should be something like B18B or B18C, or something similar.
If you shift and that light goes off, then you're shifting too soon. Now of course this is assuming you're either merging onto a 70mph highway from a standstill or you're at a track of course...hehehe... Now keep in mind that if you're even remotely concerned about fuel mileage, try to stay below 5000rpm during normal driving. Driving around with VTEC engaged is an excellent way to waste gas, and possibly attract cops (with the increased noise).
That VTEC light is definitely something the previous owner installed, along with the Japanese characters on the head
Hope this cleared some things up. Now help us all a bit and post some pictures of the engine bay, preferrably with a clear closeup of the front of the engine, if possible.