Welcome to the forum! I'm not sure there's a definite answer to your question, but it is a valid one. I think Honda made a great move by offering the Hybrids with a couple different exterior color choices, but I'm really not sure why they chose to make the interiors navy blue and tan (and whatever the other color choices are). Hopefully there's a color combo available that suits your tastes.
2008 Honda Civic Hybrid - Color Selector - the Official Honda Web Site