On my Losi mini SCT, at high throttle with a fully charged 1300mah 2s 15c lipo, the light on the Xcelorin ESC stays solid red? It doesn't seem right... Or am i just being stupid and that's what it's supposed to do at high throttle?

I've read some other threads, on some brands, solid red means a fault and on others it just means full throttle.
Is it anything to worry about?

That's normal, indicates full throttle is reached.