This is true but...My policy is that the colour and shape (design) of an arrangement is what gives the biggest impact, particularly for the sender looking at a picture.
An all pink arrangement is not a substitute for an all yellow one.
Again, this is the problem with customers serving themselves, online, there is no one there to say as I always do "The picture is to illustrate the style of the arrangement, exact colours and flowers can vary depending on what is available in that shop on that day". Having that in small type at the bottom of a web page is not going to get the message across.