Which is correct (or better) English:
"Choose lace in neutral pastel tones or also in grey or black"
"Choose lace in neutral pastel tones, in grey or in black"
"Choose lace in neutral pastel tones, grey or black"
Grey and black are not pastel tones, so you are setting up an either/or situation. Therefore, it would be proper to use the first example:
The first or separates pastel tones from the set of hues in the grey/black spectrum, and the second or offers a choice between the latter two. Note that if you said "grey and black" it would imply that you meant to use both in combination.
Also note that I put a comma in, but it is not strictly necessary. It just gives the reader a handy marker to quickly see the first of the two choices, pastels vs. grey or black.
None of these is incorrect.
But item 1 could be interpreted as meaning something different, because of the word 'also':
Item 1 could mean the 3 options are:
While items 2 and 3 mean the 3 options are:
Item 1 sounds awkward, and ambiguous, and even if the meaning as described above is what you want, I would suggest rephrasing it.
They all mean the same, and they are all grammatical. The difference lies in the tone of the statement.