Filters can only be applied to a particle system’s emitter. You cannot apply separate filters to individual cells. (Filters can be applied to the source of a particle cell, but not to a cell directly.) As a result, filters affect the entire particle system, including every element in the pattern.
For more information on applying filters to layers in your project, see Using Filters. For more information on keyframing particle system parameters, see Animating Objects in Particle Systems.