Change icon colour if users email is in SP list

[JimboSey]

Hello,

I have a gallery in my App, in the gallery is a thumps up icon, when pressed it logs the users email to my SP list column 'ThumbsEmail'.

Id like the icon colour to change from standard grey, to green if the users email is in the SharePoint list column for the selected gallery item.

I assume I need to use Lookup, and apply the code to the fill on the icon but as a PA novice Im not sure how.

Thanks

[JR-BejeweledOne]

If the data source for your gallery is the same SP list, you shouldn't need to use lookup.   Lookup would just add additional overhead that's not needed.

Consider this: 

If( !IsBlank(ThisItem.Email) && ThisItem.EmailColumn = User().Email, 1stColor, 2ndColor)