One tip is to take a look at every detail in your story. Does it matter to the story? As said above, it may not matter that the dress is yellow. If that's the case, leave it to the illustrator. Let it be purple in the pictures.
Take a look at a bunch of picture books. What details are in the text? Lily's Purple Plastic Purse gives the color in the title. Why? Sound? Yep. Character? Yep, it shows how Lily thinks of it and how special it is to her. If it were green, she might like it less. This is why that detail can't be left to chance or illustrator whim.
In this case, the color was so important it needed to be in the text. Sometimes a detail is important because plot hinges on it, but it's location in the illustration is enough. In those cases, use a note to the illustrator. Some books have a second illustrated story that riffs off the story in the text or have illustrations that contradict the tone of the text (serious text with silly images.) These ideas go in illustration notes, brackets at the end of the appropriate lines of text.
Good luck with your cutting.