Yellowing of some leave from inside out

[Sugarbayallstar]

This has happened a couple of plant 2 _3 weeks into flowering pH 6.8 hum 40%temp 28c defiency?? Only on some flowers yellowing from forming cola out yellowing clear border with green some heads totally green any advice greatly appreciated
Thanks

[Hungrybud]

Photos in natural ight please mate, and the strain.

[SlowOldGuy]

much more info and pics would be helpful,

maybe this will help…