Here are dress, hat, and a necklace for a little (toddler) Witch. From storysims.
Forest fairy flowers in her hair, from . Visit the link to see all the colours.
The artist calls this a summoning rug. I wouldn’t have added it, because I don’t want anything satanic/demonic but it is a pentacle and seems to be right side up. So, here it is, from gremlins696.
From Margeh-75, a dramatic Witch dress. More for Halloween, but I like the jewel colours. Another, in an historical adventurer style, from Philosimy.
This is a set of three: skirt, shirt, and stockings, from Birba32. I think you could have them worn together or with plainer clothes if the set is too much colour all at once. I think its fun, especially for kids.