TextBox Background colour

I'm very new at this..so Ill maybe ask lots of stupid questions.
Firstly when in designer I can set the background colour of a textbox to 'none'.  In blocks I am changing the background of the textbox to grey when the textbox has GotFocus.. is there a way set it back to 'none' once it has .LostFocus ?

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Thanks for the reply, you mean use the make a colour and make a list blocks with 16, 777 & 215 ?

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no, just use a number block and put that number inside

alternatively use Enis' solution, which you can find after doing a search like this https://groups.google.com/forum/#!searchin/mitappinventortest/color$20none in the first thread here https://groups.google.com/forum/#!searchin/mitappinventortest/color$20none/mitappinventortest/sYC77xotIPA/gM51i3qHFmQJ

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Ok cool... sorted now .. just hadn't found the number box before.

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