Printing pictures from Lexmark P6250 all in one printer?

Question

I wish to print out pictures myself, but am unsure which cartridges are best to use, not the brand, I will stick with the Lexmark brand.
I have all three cartridges, the photo, black and the color.
Which combination makes the best quality pictures?
The photo with the color, or the black with the color?
Black with photo doesn't work (both cartridges use the same slot)
I will be making two 5 X 7 pictures per sheet.

OK....how did I answer my own question????

I use my printer all the time, that is why I have the cartridges.
I do not print out pictures that often, so it is cheaper for me to do them myself than to have a print company make them for me.

Oh, well so much for advice. I just mixed the cartridges around and guessed until I found out which worked the best.
There went 5 points down the drain.
When it comes to an open vote, at least one person answered.
I just hate to give away the 10 points when it did not help me at all.

Answer 1

go to http://www.shutterfly.com Its cheaper way to go then what you are doing. Your prints will cost you about a buck apeice after you pay for all that ink they charge 20 cents a peice and 2 bucs for shipping if you order say 15 at a time you will save alot of money. Think about that.

Also you answered your own question in the question