The Mothercare covers we bought were a shiny grey colour which we think would attract children, but before discontinuing the product completely they offered only a white version on their website.
The red version of the IKEA cover appears to be intended for use as an extractor for the white one (although we found they were easy to remove without), a pictogram on the packet warns not to put it in a socket, but dimensionally it is identical. We think the red colour makes it particularly attractive to small children.
Later versions of these covers have been slightly modified. But, instead of making the the plate extend to the full 9.5 mm from the pin required by BS 1363, it is now just under 2 mm! This is just enough to cover the hole when the cover is fully inserted, but the hole becomes visible again when the cover “pops out” due to its short pins (the pins have been extended slightly, but not enough to prevent the pop out problem in all sockets). The pins remain badly shaped and the wrong thickness.