Conditional format -> formula is -> multiple arguments?


I want to apply conditional formatting to a cell with “Formula is”, but use two arguments.

I.e. I want to format the target cell, A1, if B1 is empty (for this I use ISBLANK(B1)) and if A2 contains either the text “Green” or “Red”.

I’ve tried various ways to combine arguments (&, &OR&, OR, ; etc.), but couldn’t make it work.
Example: ISBLANK(B1)&A2="Green"OR"Red"

Many thanks!

Formulae used in ConditionalFormatting need to be composed in the same way as if used in a spreadsheet cell (except the leading “=”). In fact you should “develop” and check the formula (if not obvious) in a cell, and then copy it, and paste it into the respective line in the CF dialogue.
AND, OR aren’t operators in Calc, but functions accepting an arbitrary number of parameters. Your formula should read

Thank you!