For a more advanced analysis (e.g. if there are dozens of entries and you don't want to reduce the transparency X times), you can:
- use a transform column to calculate 1/0 for data with & without marker (here: fruit = "Pears")
- use this transform column as "color"
- then you just have to adjust 2 settings instead of dozens of entries

Graph Builder(
Transform Column( "Rosy", Nominal, Formula( If( :Kid == "Rosy", "Rosy" ) ) ),
Variables(
X( :Days ),
Y( :Values ),
Overlay( :Kid ),
Color( :Fruit ),
Color( :Rosy )
),
Elements(
Line( X, Y, Color( 1 ), Color( 1 ), Legend( 1 ) ),
Points( X, Y, Overlay( 0 ), Color( 2 ), Legend( 2 ) )
),
SendToReport(
Dispatch( {}, "400", ScaleBox,
{Legend Model(
2,
Properties( 0, {Transparency( 0 )}, Item ID( "Missing", 1 ) )
)}
)
)
);
If there is a conflict for overlay or color, you can disable or enable them separately for specific graphs:

In Graph Builder, this can be done via the variables drop down menu:
