Cap color is one indicator that a pep may be from the same batch. If two people order the same thing from the same vendor around the same time and the cap color is the same, you likely have the same batch. Sometimes we know that vendors share sourcing, like WBS and ERP, so again same cap color, product, and time, likely the same batch.
At the same time, earlier this year several vendors were selling T30 with orange caps. There were problems with the Jeep batch but the ones from ERP/WBS had different sourcing and no issues. So people took a real good look at any T30 with an orange cap becuse it could have indicated common sourcing.
So its not meaningless, but you have to be careful how much meaning you attach to it.