What did Colbert mean by “bedude form"?
Solution 1:
As per a comment under the question, bedude is not a word. However, bedewed is.
From bedew:
[Merriam-Webster]
: to wet with or as if with dew
We can assume that's the word he's pronouncing—and presumably he's describing the sun shining off of water droplets on her body. (Although, oddly, the YouTube closed-captioning used specifically ignores that single word—even when it's spoken a second time.)
Solution 2:
He may have said or meant "benuded", as in "made nude".