Inverted Values On A Form

I would like to have a control on my form which displays the opposite value to that stored in the table.

ie, if the table says "TRUE" then the form should display false.

Having the value displayed is simple enough.
I have two fields on the form - Field1 is the value from the table and is hidden and DisplayField has a RC of =not [Field1]

DisplayField always displays the opposite value.
However, when I click DisplayField I am unable to change the value as it is "bound to Field1 and cannot be changed".

Elsewhere in the database Field1 is used in its normal form so simply changing the field is not an option and to save space I do not want to add another field which is simply the opposite of this one.

Is there any way to of updating Field1 when DisplayField is clicked?

(Note: this must be on a continuous form and the values will not be the same for each entry!)

Any ideas would be gratefully received.

Cheers.

PS (this is probably on here if I search, but whilst I am typing...) is it possible to change the colour of a single row of a continous form based on the value of a field? ie, red text if a value is false, green if true, as you can on a report