When heating liquid materials in laboratory glassware

Da glass starts to melts and mold to get the solution that u r wanting

Explanation: because whenever u melt glass it gets slimy lookin and sometimes when u but heat to it it turns black

the father in the first generation probably had the recessive colorblind trait in his x chromosome. if he and his wife both had the colorblind trait, even if she had 1 recessive and 1 dominant, then that trait would be passed on to their kids.

(since you didn't attach the family tree this is just an assumption)