First one I came up with was:
Red Rebellion - It sounds cool and it rolls off your tongue easy (he's a chestnut btw)
The second one was following along the same lines as the first:
Crimson Courage - again because it sounds cool, but is slightly more positive than the first.
Then I got to thinking that it should have something to do with "honest" in it, as my instructor keeps telling me what a kind, honest horse he is. So...
Honest to Goodness
In All Honesty (my fave!)
So what do you think? For reference pictures go here - Critique Shea