More than one person has observed that accumulation of red fluorescent protein leads to a deep pink color that is visible to the naked eye without fluorescence imaging. Can it thus be quantified in a similar manner to chromoproteins such as amilCP?

I ask this this question in relation to the pClone system published by Malcolm Campbell and Todd Eckdahl, and a follow-up paper by Anthony Forster.

Article pClone: Synthetic Biology Tool Makes Promoter Research Acces...

Article Overcoming chromoprotein limitations by engineering a red fl...

Thank you for your input.