For plasma, there are several ways.
The "crossbar" is always a certain shade of orange, and always along the same line (pixel scan it's color)
The "connection field" is also a certain color (depending on plasma being farmed) and along the same area, and is always the same width (around 62px, forget).
If $crossbar > $connection and $crossbar < $connection+62 then
I might post some functional autoit snippets for people at my blog:
Oh, and multiclients for 1.227U
This isn't Vincent's release however, did it myself. Tested on two machines.
The blog (^) has a brief "howto" in it if you'd rather do it yourself.