Looking at the shading he used for the CoAs of Bulgaria (
link), Croatia (
link) and Dalmatia (
link) amongst others, he seems to have followed this convention:
horizontal shading = blue (azure), vertical shading = red (gules), dots = or (gold).
So I think Thrace is a gold lion on blue - not sure what the circle above the lion is meant to be, but it's gold too.
Moesia is a crown and inverted crown on blue - the crowns are probably depicted 'proper' i.e. in normal colours, so shadings of gold with gems in other colours (which I can't make out at this resolution).
Edit: 'red' for Moesia was a mistake - corrected to 'blue'