Hmmm... I've got an extra pale gray, which may be too light, but I may also have an extra red. If not, a quick swing by Target should offer up a range of possibilities.

The transfer came out beautifully, by the way! Now I've got 5 more sheets and a nearby Target selling T-shirts, and burgeoning plans. The world needs some Sarah Jane Adventures T-shirts!

Already dropped the TARDIS design onto my thumbdrive for you.