Custom variable in background expression

[Shniperson]

Hello.

I'm trying to change background in table and wonder is it possible to create some "local" variable in background color expression? Something like this pseudo-code:

let x = SOME_VERY_LONG_EXPRESSION;

RETURN if(x < 10, GREEN(), if( x<20, BLUE(), if (x < 30, RED(), YELLOW())))

Because X is long expression so using it in every if statement is totally unreadable. And I do not want to create global variable - I have this expression only in one place.