Increase variables when multiple selections are made

Hey guys -

Quick question, I need to increase the number of output variables as multiple items are selected. For example, let's use something basic:
Colors (Pick Multiple) - Form Type Radio
Blue
Red
Yellow
Green
Black
Purple

So the normal output is something like:
[colors] => Array
(
[0] => Blue
[1] => Purple
)
I can implode using the handle arrays function on the submit, but what I need is to increase 'colors' for a message display like this:

[color1] = Blue
[color2] = Purple
...

Not a coder, at all, so any help appreciated.
Mike