Hello,
The first example in Variegated yellow with green handles is a piece I would say is theirs for sure. Here is an image of a a distinct shape by Welz done in the same decor and handle color. This piece is not mine, and the image is used with the board members permission. This is not a commonly seen color combination. I have seen it a couple of other times, and always on the geometric trophy. That particular geometric trophy shape was shown in the Welz cases in the 2012 Tango Exhibition in a pink Variegated with clear handles.
The second image I am attaching is of a group of similar pieces to the yellow example you have. In the case of these 4 pieces, although the bowls are different than yours, they all appear to have the same foot/stem as your example.
I am confident stating the yellow example is Welz productin.
The second piece is a decor used by Welz often, but it is not a shape I have seen before. Certainly does not rule them out though. I would say more likely than not that it is Welz production.
Hope this helps.
Craig