[Justa]

Dude, go for broke. Check out the last frame of the sequence. There's a 'flare' of white as the debris approaches the exhaust. That ain't insulation, it's steam!

[bonesmccoy]

I'm not sure which frame you are viewing :(

I'm looking at the KSC PAO mpeg E212.

The last two frames show the plume to be expanding and still present as it passes into the SRB and SSME exhaust plume. If silica tile dust passes into SSME exhaust, does the SSME exhaust plume change color?