Samsung's One UI allows dual SIM users to change the icon for the SIM cards. Samsung provides different colors and icons for this purpose. For example, there is an icon especially for a SIM card that is only used for mobile data use. In the same way, a SIM card can be marked as "Private" or "Office". The following types are available:

Android 10 (One UI 2.0)
Step 1:  Open the  Settings
Step 2:  Tap on  Connections
Step 3:  Tap on  SIM card manager
Step 4:  Tap on  SIM 1 / SIM 2
Step 5:  Tap on  Icon
Step 6:  Choose the  Icon  you want
Step 7:  Confirm with  OK
  1. Open the Settings
  2. Tap on Connections
  3. Tap on SIM card manager
  4. Tap on SIM 1/SIM 2
  5. Tap on Icon
  6. Choose the Icon you want
  7. Confirm with OK

Samsung Instructions