Why are funds that transfer OUT of an account colored black and red when an account receives it?

AtlCenter

When I run a bank summary report and look at the transfer section I get confused at the positive and negative indications.

Example

When I make a payment to a credit card account I transfer the funds from checking to the credit card account. The funds transferred out of the checking account show up as Black or in my mind a positive number even though that account is reduced in funds.

The transfer to the credit card account shows up as red.

Can someone explain the logic of this?