Hi Stellajo,
Currently LR doesn't have the ability to handle .gif animations, bold, italic, or underlining, but changing the font colour for a specific word in a sentence is doable.
Simply select Split Mode from the PLAYBACK SETTINGS tab in PLAYBACK, and then decide the colours for Split Mode. For example, if you choose red and blue as the split colours and then type the sentence:
Yesterday, I went to the /park/ and played with Mummy!
It will display as:
Yesterday, I went to the park and played with Mummy!Hope that helps!
shuki