I am not sure if I understand your question right. You need a leg cover (aka apron) you sent me the link to (looks nice, btw!), and you are asking me if this same one is available in the same colour your stroller/pushchair part is in? As this is a universal foot cover, it is only available in those colors they offer it, which, in this case, is the one you've sent me (Grey Melange) and then a darker one (Black Melange). I personally would pick any of those as the fit will be OK while not the exact same color your pram is in.
If, on the other hand, you're asking me about a different leg cover that would match your stroller exactly, I am sorry to disappoint you but there is no original Beemoo apron available - they don't have a dedicated one. Any grey of any brand or kind will simply not be a 100% shade fit as greys vary considerably and if not originally made for your pram, they will simply be a bit different.
My suggestion for you would be to not care that much about the exact fit, just own it and color match different colors - it will still look nice! I am attaching a cosytoes in a Beemoo (source being Linda Blom) that doesn't fit exactly and still looks very nice - for inspiration! 😉