Theoretically a skilled person in computer editing (colors and such) could do a more or less scientific test:
1. Shoot a good picture of a shoe you have at hand with your own camera that has two distinct colors for the shoe itself and the shoestrings.
2. Roll a dice as often as needed in order to either get the number "1" or the number "6"
3. If you roll the number "1" first, take the picture you have made of the shoe and change the color of the shoe itself and the shoestrings (via editing skills on the computer) into two different distinct colors of your choice, so that the original colors can't be seen anymore.
4. If you roll the number "6" don't do any editing of the picture of the shoe at all
5. Don't disclose to anyone what you did
6. Upload the picture of the shoe here and ask everyone what colors they see
7. After a sizeable number of people here have disclosed what colors they see, disclose what you did (aka. edited the colors of the picture or not)
You could also go a step further and do the same experiment above again a number of times and put it up here with different colors (if number "1" is rolled on the dice first). In this way you could diminish the chance that someone could see the original color in the roll dice scenario where number "6" has been rolled on the dice first (aka. the picture was not edited). Because theoretically, those who apparently "can see the original color" could also then see the original color of the shoe and shoestrings before they were colored in the original shoe you have in front of you.
1. Shoot a good picture of a shoe you have at hand with your own camera that has two distinct colors for the shoe itself and the shoestrings.
2. Roll a dice as often as needed in order to either get the number "1" or the number "6"
3. If you roll the number "1" first, take the picture you have made of the shoe and change the color of the shoe itself and the shoestrings (via editing skills on the computer) into two different distinct colors of your choice, so that the original colors can't be seen anymore.
4. If you roll the number "6" don't do any editing of the picture of the shoe at all
5. Don't disclose to anyone what you did
6. Upload the picture of the shoe here and ask everyone what colors they see
7. After a sizeable number of people here have disclosed what colors they see, disclose what you did (aka. edited the colors of the picture or not)
You could also go a step further and do the same experiment above again a number of times and put it up here with different colors (if number "1" is rolled on the dice first). In this way you could diminish the chance that someone could see the original color in the roll dice scenario where number "6" has been rolled on the dice first (aka. the picture was not edited). Because theoretically, those who apparently "can see the original color" could also then see the original color of the shoe and shoestrings before they were colored in the original shoe you have in front of you.