Michael,
I discovered that if you put the following script into a button with
it's autoHilite off, you will get a very smooth transition albeit
slow. It takes about 5 seconds on my machine.
on MouseUp
put "0" into clr
repeat 255
set the backgroundColor of me to clr,clr,clr
add 1 to clr
wait 1
end repeat
end mouseUp
Can you work with this?
Cheers, Roger