Janet,
I have not posted for a while, but I have just been hunting for a match for my blue RST.  The paint finish on mine is not great, lots of random rust and pealing paint,  the other 2 thorn frames i own the paint is much better.
I used humbrol enamel met 222 from hobby craft.  It is not 100% but is is very close.
All the best.
Peter.