So what makes something "fiery"? is it the color? Nah... i don't thing so. Fire is a feeling - so you can use fire as an inspiration even you don't really make it look at all like fire. Like this heart - it feels fiery, doesn't it? so yeah, it's the flame shapes and the fact that they dance upward, like fire usually does. Hmmmm, now that i think of it, fire can be green, if you put the right minerals in it. Well, you know what i mean - you can make your art hot in all kinds of ways! Even green ways!
Have fun with that this month.