use two consecutive transformation in XSL

Hi,

I want to use an xsl stylesheet to transform a cMathML to pMathML code and after doing that I want for example to use another xsl stylesheet to do another tranformation for example to change the color of the mathematical formula that results from the first transformation. is it possible?

I have another problem: When I transform only some tags of html document the effect of the others desappear.

For example if I transform <strong> and I don't transform <i>. <i> have no effect.