Yeast Y17097( Δgsh1) strain was affected by different strength pulsed electric fields generating oxidative stress to cells and causing cell death or presumably mtDNA mutations. I want to detect respiratory deficient yeast mutants by performing TTC agar overlay technique (Ogur et al). Final concentration of TTC 0,1%, evaluation after 3 h is not enough for petri dishes with more colonies. Results I got is red and pink colonies but no white colonies. Is it possible that pink colonies indicate RD mutants? Or some sort of mutants that have defective respiratory chain?

P.S. I add some photos of dyed colonies