My hp4780 will now not print in color. It did before.

[Harvey54]

My printer printed in color for years. I have changed the ink supply many times during this time.  When I print out the alignment page now it only prints in black and white.  It will now only print pages in black and white.  

HP PHOTOSMART C4780

serial no. [edit]

FPU  Q8380-64002

My computer:

Model Name: MacBook Pro

  Model Identifier: MacBookPro13,1

  Processor Name: Intel Core i5

  Processor Speed: 2 GHz

Serial Number (system): [edit }

 Hardware UUID: 8CD06F10-2F25-5D6B-AF33-51B23390454E

[8lives]

Have you tried replaceing the color cartridge?

[Harvey54]

I have tried three different  NEW color cartridges.  I have looked up numerous suggestions online but no success.

[8lives]

Looks like a internal printer problem.