Samsung
Change SIM Card Icon auf Samsung
On a Dual SIM Samsung phone, both SIM cards can end up sharing the same icon and color in the status bar, quick settings, and call log. That makes it harder to spot at a glance which SIM is set for mobile data and which one takes your calls. One UI stores the icon assignment inside the SIM card manager, separate from general connection settings, which is why many users never notice the option exists.
To change it, open Tap on Settings ➔ Tap on Connections ➔ Tap on SIM card manager. Pick the SIM you want to customize under Choose a SIM card (Dual SIM), then select Tap on Icon. Choose from the available icon and color set and confirm with Choose a SIM card icon and tap OK.
The new icon shows up wherever that SIM is referenced: status bar, call screen, and messaging app if it displays sender SIM info. This only changes the visual label, not the actual SIM behavior, so it will not affect network priority, default data SIM, or call routing. If your issue is actually about which SIM is used for calls or data rather than how it looks, check the default SIM settings instead of the icon option.