help required with complex (well, i think so) statement in power query

let
    Source = Excel.CurrentWorkbook(){[Name="Table4"]}[Content],
    ChangeType = Table.TransformColumnTypes(Source,{{"Start Date for Next Activity", type date}, {"End Date for Next Activity", type date}}),
    today = Date.From(DateTime.LocalNow()),
    Result = Table.AddColumn(ChangeType, "Indicator color (as of " & Text.From(today) & ")", each let 
                startdate = [Start Date for Next Activity],
                enddate = [End Date for Next Activity],
                progress = if [#"% Complete"] = null then 0 else [#"% Complete"]/100,
                plannedduration = enddate - startdate,
                targetdate = Date.AddDays(startdate, Number.Round(Duration.Days(plannedduration)*progress)),
                daysfromtarget = Duration.Days(targetdate - today)
            in 
                if progress = 1 then "GREEN" else 
                if today > enddate then "RED" else 
                if Number.Abs(daysfromtarget) <= 14 then "AMBER" else 
                if daysfromtarget > 14 then "GREEN" else "RED") 
in
    Result