Just some ideas, perhaps some of which could be considered.
Additional Features:
This power could give a colour effect from a crayon to any smile too! By this, a regular smile could appear coloured in by a crayon.
A smile of large length which allows a small message to be written in crayon (with the motion of the crayon being shown). This could also be done like the ‘popspeech’ smile.
A hug which includes a message written in crayon, perhaps even a drawing in crayon if we could somehow hook this up to the doodle app. Alike above, the crayon motion could be shown. If this option was to be implemented with the doodle app, could we perhaps allow a certain number of free hugs in main chat?
Pawns/Hats:
A crayon replacing the pawn (with the colour of the crayon being based off the current rank/colour power on display).
A regular pawn, but the colour of it has a crayon effect (to replicate it being coloured in by a crayon).
A further option to the regular pawn with the colour of it having a crayon effect is having the crayon also making a colouring motion on it. (This is similar to typing power - perhaps we could replace the pencil that appears when typing with a crayon if both powers are enabled).