conditional formatting issue

I have a text box on a continuous form behind the other controls, that I want to colour differently with conditional formatting

I have set it to locked yes, enabled no - but the conditional formatting seems to make it enabled yes - and when you inadvertently click it, it brings it to the front. I can't see a way to keep it as not enabled.

is there a way round this with a text box?

it doesn't look like I can conditionally format a label?

conditional formatting issue