How do I make a rainbow pen but only until I press something else AKA I only want it to be rainbow after I press something and end when I press something else?

when green flag clicked
set [Pen v] to [0]
forever
    
if <key [space v] pressed?> then
    
wait until <not <key [space v] pressed?>>
set [Pen v] to [1]
repeat until <not <(Pen) = [1]>>
    
change pen color by (3)
if <key [any v] pressed?> then
    
set [Pen v] to [0]
end

end



end

end

I hope I helped!

Thanks!