After a little investigating, I've finally made some time to go into detail on my own take on this whole 'Executor' thing now adywan, so here goes -
While disappointed with their lack of care and attention in many areas, I ended up abandoning my old videotape versions when the long-awaited 'special edition' DVD versions appeared in 2004...and it seems that I got so used to seeing the hateful, new 'blue-tinged' colour-timing over and over again in the years afterwards, that I eventually ended up completely uncertain about what was what concerning that particular 'tower' close-up...
But while it looked slightly more on the 'blue' side compared to some of the subsequent SD shots just afterwards, it wasn't quite as strong a 'blue' colouration as the eventual 'underside' reveal of the 'Executor'...and so I just carried on thinking that the 'tower' close-up was really just a 'standard' Stardestroyer in the overall 'gathering/regrouping fleet'...whose huge scale was then eventually seen to be 'shadowed' and dwarfed by the even bigger scale of the 'Executor' ship afterwards.
And as others have firmly suggested, that progression of events can make for an excellent 'cinematic'/'editing' flow to the sequence. And for years, I was happy to view it in the same way too...until I eventually ended up coming across a link to this 'technical journals' page at Theforce.net site - http://www.theforce.net/swtc/towers.html#introduction , which had several screenshots of the 'tower' in question, such as this...
The colouration on this really muddied the waters for me at the time (2009!), and I realised it certainly wasn't a shot from the 'special edition' DVD or faded GOUT release, so I asked how *you'd* interpreted this particular 'tower' colouring...and here's my exact post with what I asked... - http://originaltrilogy.com/forum/topic.cfm/STAR-WARS-EP-V-REVISITED-EDITION-ADYWAN-BATTLE-OF-HOTH-CLIP-NOW-AVAILABLE/post/386181/#TopicPost386181
...and the answer I got shown afterwards showed this...
...so that *absolutely* cliched it once and for all for me these last 4 years...it was definitely the 'standard' Stardestroyer that would be eventually 'shadowed' by the 'Executor', after all! :)
Or so I thought until now, lol.
To sum up, I can easily see a case for this 'tower' close-up as being the *actual* first glimpse of the 'Executor's' massive size...just as I can equally see how the sequence also works well if it seems that we see the 'Executor's' underbelly section first. So whether you end up wanting to make it 'blue' or 'grey', I'm gonna be equally happy with the outcome thanks to all your terrific enhancements to the sequence.
Just don't make it 'purple', thanks. :)