Can I cut chili powder with Paprika?
This recipe list chili powder as:


2 tablespoons paprika
2 teaspoons oregano
1 1/2 teaspoons cumin
1 1/2 teaspoons garlic powder
3/4 teaspoon onion powder
1/2 teaspoon cayenne pepper, or to taste (optional)


There are other mixtures, but this one seem basic enough. The "heat" comes from the cayenne pepper. The other spices round out the flavor. 

So I'd mix everything but the cayenne pepper and use that mixture to cut your present chili powder.