To recap the exact flow:

Once activated, the menu is not visible in the main settings list. To find it: Additional settings System settings on some versions). Scroll down to find and tap Developer options Key Features to Explore

Tap on (this is usually a separate sub-menu within About device). Locate the Build number and tap it 7 times quickly.

Inside the “About Phone” section, look for (or directly “ColorOS Version” ). On many Oppo A38 devices, you might see: