The departure from tradition I was referring to is for a Queen Consort to wear two robes - a crimson and a purple. The previous three Queens Consort wore only their purple, from start to finish.
I think it's quite understandable that their purple robes would not really be recyclabe because they have extremely elaborate embroidery and were specially designed for each. I think a new purple robe is understandable for the Queen Consort.
Here is Queen Elizabeth the Queen Mother viewing hers at an exhibition.
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