Years ago OWC had one of their OWC Aura blade SSDs which appeared with an orange icon even though it was installed internally. Later OWC released a firmware update for the SSD in order to work with later versions of macOS (I think it was for Catalina) which also got rid of the orange icon for the SSD. IIRC, the reason for the SSD firmware update was because macOS no longer supported RAID and that OWC SSD had its NAND chips on the SSD in a RAID which was visible to the OS apparently. No idea whether that was the reason for the SSD to show an orange icon or whether it was some other bit in the SSD's firmware.
My guess is the PCIe card is probably causing it, but it could perhaps be the SSD. You will need to contact the PCIe card vendor to note the issue to see whether they can resolve it with a firmware update.