polychromatophilia

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Affinity for more than one type of stain, especially for both basic and acidic stains.

from The Century Dictionary.

• noun The condition of the red blood-corpuscles, in which they take both acid and basic stains; polychromasia.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The affinity (of a sample prepared for microscopic examination) for more than one kind of stain, especially for both acid and basic stains
• noun polychromasia, a disorder of the red blood cells