IGV read color ,what is inferred insert size and expected insert size mean?

Question

[Tao]

why this read pair is red in IGV? I see the IGV doc,read pair marked in red means inferred insert size will be larger than expected, How to calculate the expected insert size and inferred insert size?

[GenoMax]

See the illustration here : What is the difference between a Read and a Fragment in RNA-seq?

Insert size is calculated based on the alignment of the two reads to the reference genome.

[Tao]

I understand how insert size and fragment length are calculated, but I don't know inferred insert size and expected insert size. Inferred insert size larger than expected will be marked in red,but how to know it should be red.

[GenoMax]

Not sure what you mean by "how to know it should be red"? That is the color scheme IGV is using based as noted in the shot you posted above.