qwilder,

1. Depends on your program version:

In newer ones select the video object on the timeline and go to 'Effects' >> 'Video effects' >> 'Chroma key' and click on the green option -- color to be hidden.

In older ones eg MEP14+, do a right click and pick 'Video effects...' [Shift + Y] and use green box 'Mix FX".

In both cases there are threshold and fading range sliders to make fine adjustments.

2. Paint's OK -- some users find it easier to use a green sheet or tablecloth as long as it can be hung free of wrinkles and shadows. Color should be as 'pure' as possible (no red or blue component (eg chartreuse or turquoise), though the sliders do allow for a reasonable variation.

Success depends a lot on how evenly you can light your screen. Most important is that your foreground object doesn't have any of the same green. Note also that there are options for blue screens (& B or W) as well as picking an arbitrary color.

Regards,

Carl