4 Sticks in Dual Channel

Last time I built a dual channel rig was for a AMD 3000 64 rig so wanted to make sure things have/haven't changed.

Looking at Core 2 Duo motherboards and notice a lot of the ones with places for 4 dims have 2 slots colored one way, and another 2 slots colored a different color.

Does this mean I can run 4 sticks in dual channel now?

If so do all 4 sticks have to be exactly the same or jsut each pair?

Thanks in advance

Its best to keep everything the same, Same size, Same Speed, Same Brand, Same latancy, etc. I know on my older system if I put 2 or 3 different speed sticks in, it doesnt run that well.

Actually, on many MBs (usually Intel), it doesn't even mean that. Many will run in dual channel as long as you have the same *amount* of RAM in each channel (e.g. 2x512 MB=1GB in one channel, and 1x1GB in the other channel). Some will even run in a "partial" dual channel mode if you have different amounts of RAM in each channel, where it will run in dual channel up to the smaller amount of RAM, and the extra will run in single channel.
You need to read the MB manual to find out exactly what your MB supports.