Use [Set Var -> Item Manipulation -> Set Potion Effect] with the var you want to set, a water bottle, and a potion var for what you would like to set. You can set the name through [Set Var -> Item Manipulation -> Set Item Name], and color through [Set Var -> Item Manipulation -> Set Item Color]. For the color, you will use a hex code in a text var. You can use a hex color picker from this link.
Use [Set Var -> Item Manipulation -> Set Potion Effect] with the var you want to set, a water bottle, and a potion var for what you would like to set. You can set the name through [Set Var -> Item Manipulation -> Set Item Name], and color through [Set Var -> Item Manipulation -> Set Item Color]. For the color, you will use a hex code in a text var. You can use a hex color picker from this link.