This is a place to ask parenting related questions and get some insight into how to handle things.
Answer: Two year olds love to be helpful and that means doing everything that they see you do. If what they see is the joy in picking tomatoes then they want that also. The child is not focused on the color. They are centering on the picking. Therefore involve the child in other tasks related to the garden. Also have times that you take her over to look at the tomatoes and touch the tomatoes gently and say ”they are not ready yet.” And then leave them alone. Teach colors and ready versus not ready.