Upon challenge from https://derpibooru.org/1462205#comment_6231380 I made this to show definitivley that Celestia's fill is very consistently an off-white pink.
I don't like using absolutes like this, but here it's warranted. This is not something that is up for debate, this is a known and verifiable fact. Celestia is not white, in much the same vein as Rarity is not white, they are both off-white in the show regardless what any writer or anyone else has to say about the matter.
Also, since I forgot to mention, I did source all of the screen caps from the MLP wikia. I was partially tempted to go and actually check some of the earlier episodes myself to see if the inconsistencies were caused by caps from different sources, but I decided that this wasn't necessary as the results gathered more than prove my point despite the inconsistencies.
Another thing I neglected to mention was that the swatches were obtained by sampling a 5x5 area of color, as to reduce the chance of picking pixels that happened to be discolored by image compression or things such as that.
Other than that, feel free to ignore me. For what it's worth, I Was Never Here
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