Help with color expression

[CasperQlik]

Hi Qlik Community

I'm having some troubles with conditional coloring.

I have a line graph like below with 2 measures. It is the 2 measures in %. 

I need to color each line with a distinct color code and not the default values.

I'm using the color by expression but cant get the desired outcome. I have a flag that should control the color.

When flag_field = 1, color 1 and when flag_field = 0, color 2 should be applied.

Any help is appreciated.

[Amit_B]

If I understand correctly, try as I did in one of my apps:

I defined the following expression in a variable:
='If(Year = Year(Today()-1), RGB(87,97,204), RGB(158,158,158))'

In the line chart I set the variable like that:
$(vYearColor)

[CasperQlik]

I used a master measure to get the desired result.