I have a booklet of these stamps myself (with the VW camper van on the back) and looking at the bobsled it seems blue-ish enough to me but when scanned it looks kind of grey-ish.
I know my scanner could be off, my monitor could be off, I could be off (we won't go into that right now!). Lots of reasons for seeing colours in a certain way.
My booklet:

Zoomed in:

So . . .
What could change the colour of those used stamps in the auction? Just the greyish-blue?
Does anyone have any of these stamps and noticed any colour differences / changes at all themselves?
The auction is up to $6.50 now, 45 minutes to go.