Slipper pads
 

I've just received some replacement slipper pads that I ordered.
I was expecting them to be the orangey brown colour but they are actually white.
Can anyone tell me if there is any difference between the two?
Is one type better than the other?

They seem to have the same part number, were the white ones superceded by the orange ones?
If so, when did this happen?

Thanks in advance for any info offered.