Text selection highlighting with non-editable and readonly field

Is it possible to have highlighting for selected text in a non-editable and readonly field?
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The selected “xmlns” is copyable, but not highlighted, so user doesn’t know what is he copying.

Selection is visible for me in an uneditable read-only editor. What exactly do you mean by ‘highlighting’ in this case?

Ah you are right, the selection simply has the same color as my background… Thanks!