dragCoefficient is the ammount of drag each particle has, for example if it was 1, the particle would gently lose velocity and eventually just sit there.
gravityCoefficient is how much gravity has an effect on particles, 1.0 will just pull them down to the ground, -1.0 will make them fly up.
inheritedVelFactor is how much the particle will inherit the velocity of its emitter.
constantAcceleration is basically the acceleration that the particle will always maintain.
lifetimeMS is the lifetime of the particle in miliseconds. 1000ms = one second.
lifetimeVarianceMS = the extent of the variation of the liftime of the particle in miliseconds.
the colors are done in the format RGBA, as in Red, Green, Blue and Alpha.