Quadcopter with arduino

Hi,

I am programming arduino to be a flight controler of my quadcopter. I am configuring the pitch, roll and yaw in my algorithm but I have a question: I bought 4 propelers, 2 are orange and 2 are black. The 2 orange are not equal, they look differente. The same happens with the black. What does that mean? The 2 orange must be used side by side or in the oposite side of my quad?

You need two clockwise and two counter-clockwise props, presumably the orange and black colour coding is for front and back so you can tell at a distance which way your craft is oriented

The clockwise props go opposite each other on the diagonal, so one will need to be orange and one black. Ditto the CCW.

1) Go and get a set of spare props now, you will damage them and its really annoying to have to wait for spares.

2) Remember to set the motor polarities correctly so every prop is lifting (and not pushing down!!).

The orange are probably GWS. There are two flavors of props. Slow Fly & Electric. They are different designs. What is the size & pitch of your props and do the orange ones seem to have more of a curve to them ?

Your not even close. IF the orange ones have more of a curve on each blade than the black ones that means they are SLOW FLY and the black ones (straighter and less curvature on the blade) are ELECTRIC.
SLOW FLY & ELECTRIC are APPLES & ORANGES. They should NEVER be used together because they are
designed for two different applications. You need to find out what type you should be using. I would assume
you should be using ELECTRIC only. Throw away the SLOW FLY (or get rid of them) . They have no place in
your application. They are designed to move more air and take a bigger byte out of the air. A quadcopter needs props that rotate faster with smaller byte so you have better control. Your whole FRONT/REAR question is nonsense. You never mix slow fly and electric props on a quadcopter unless you want it to crash.

The 2 orange are not equal, they look differente.

Perhaps you should provide a link to the propellers you got.