ERMM .. itz kinda hard to exlplain all tha details but you hafta make a layer fer each animation
fer example: if yoo wanted to animate a word .. lyke this

.. you would make a layer fer each letter .. layer one : only the M would be pink .. layer two: only the O would be pink, etc .. nd in the palette under yer image .. there are also layers .. example: fer layer one: only show the layer wit tha M as pink by clicking the EYE icons next to the OTHER layers dat you dunt want to be seen .. nd so on ..
ii dunt kno if you can understand dat .. but datz the idea .. if you kno photoshop .. den it'll be kinda tha same