If someone is using blue, switch to yellow, or ocasionaly red. If they are using yellow, use yellow or red to counter.
If they use red, use any of them since they all have about the same chances, except red will penetrate the guard more often, but yellow and blue is easier to time between thier red slashes.
Overal keep em guessing. If they see you switch to a stance, as soon as they start moving in or just before you move in switch stances again to trick them. Very often when you stop and change to red for example they will now be expecting a red strike. Well as soon as you start moving change to another stance so they can't see whatr stance it is till it's swung.
I go to blue when I need to do some quick damage or do a lot of fake outs.
For example, the lung is a fun move if done in the air. What I mean by that is, do a back flip then pres and hold foreward and crouch then hit attack. as you flip around backwards you will do the lung to right back where you started the backflip. It's good against yellow DFA spammers, and even backstabbers since lunge will usualy guard well VS backstab, and break through the backstabbing saber (but not always so use it mainly for DFA counters).
For yellow, I usualy bob side to side in an attempt to first swung left or right, then back again without too much of a dely between swings. what this does is quickly attacks both sides of the target in quick succession. Often getting past the guard.
Red stance is pretty much my damage stance. When I need to even the score real quick, or have better guarding. I use overhead chops on remotely stationary enemies, which has the highest chance to break through guard, and side strikes to fake out oponents (run left swing and run back at the same time.).
DFA only when they are set up just right or when I want to make them nervous (sometimes it's good for getting away so long as you jump right after the animation ends to avoid a counter).
Combo's in red are cool if you can land them... but in the heat of battle it can be hard to get all three combo swings to occur, so I usualy only consiously go for two at a time... for example, if a guy is standing still baiting me in. I will run forward and do a downward chop, but make sure I will miss... this will usualy pull in the defensive guy hoping to hit me, but if I hold down the same direction I usualy do the second downward chop, smacking them on the top of the head as they come twirling in.
A word to the wise however, if someone is using blue, and your using red, be careful if they are a twily headless chicken. they will hit you 2 or three times every time you come in to attack them by breaking thier guard. tyou will break thier guard about 50% of the time or so, but do less damage, and they will hit you up to three times for 60 damage (sometimes). so against a blue, keep your distance, and play it smart, don't rush them too much. Only get close to break the guard when you can time it so it will happen when they can't hit you somehow.
However the best thing about the 1.03 patch was that saber combat does take a tiny bit more skill now in the ways saber fighting should. Don't get me wrong in 1.02 it took skill also, but in that version it was too much like jousting. Now you can fight like you would imagine you would. you can be right in someones face blocking and timing your counter swings to take advantage. Before the best defense was just to not be in the way of the saber. now you can be in the way and still be on top.
We all have to die, the only question is... Do you want it on your feet? or on your knees...