Due to the translucent quality of ink, when printed over a transparent stock, the colors will be see-through and might look a lot lighter than they do when viewed on screen.
The surface which your transparent sticker will be placed on will greatly affect the overall look of the sticker. For example, when a transparent sticker is adhered to a white surface, the colors will appear more vibrant, opaque and closer to how they look in your proof. If the sticker is placed over dark colored surfaces, it may reduce the visibility of your printed design. Additionally, when a transparent sticker is placed on a clear glass or a window, the colors can appear very light and will be the most see-through.
Overall, we recommend using dark colors when designing for transparent stickers and to avoid light colors as these will appear more translucent when printed and reduce the visibility of your printed artwork.