Try adding hue and saturation to that layer with the option set to colorize. I don't have time to download the comp and dig into it but I did look at the preview. The flair goes to full white and there's not much you can do with full white except fill, multiply, overlay or colorize because 100% plus any value is still going to be 100% (white).
If that doesn't work please just give us a screenshot of the comp with the layer containing the flair selected and all properties revealed (press the u key twice).