Hi, I need to change font colours @ 15 minute incrimants.

if c1 is 05:00 how do I get the font to change colour if d1 is by
15,30,45,60,75,80 minutes etc.

Blue if by 15, red if by 30, yellow if by 45 etc.

I hope you understand this explanation.

Thank you in advance,

Extreme novice.