@Hunter I'm sorry I can't even remember what project I was working on when I asked this question. Just quickly opening up my Xpression Designer and tossing something together, I figured one way is this...
-Layer Object
--Background
--Quad1
Quad 1 having the material blending mode set to multiply will work. (I'm using version 5.5 build 2722, the order might be different depending on the version your running.)
Sorry again for not being able to remember exactly what I was working on at this time. If it comes to me sometime during the day, I'll make sure to check back and post.
#XPression