Hi Brendan,
Congrats on the new hatchie.
The red on males chests wont show untill a mature age,It is a form of breed dress which brightens when searching a female.If you had a few you could determin the sex by looking at there snout.Males have longer snouts than females straight from the egg,Also males may be larger due to being more dominate at feeding time and they may show a hemipenal bulge at the base of there tail.Although this wouldnt always be reliable you would get a rough idea on the sex of your new dragon.
Hope this may of helped...