Hi Pushkin!
You have few solutions for this blocker depending on your needs:
Local storage:
You can use the user’s local storage and set the value of the box at the first time of choice.
Use the wix-Storage API to save a value in the local storage (like cookies/cache).
Note that if the user will clear his local storage, the setting would be lost.
Query params:
You can use query params in order to navigate to the next page by the wanted value of color depending on the box clicked. Follow this API in order to use the Query params and simply add to the query the color according to the box that was clicked.
Boolean field:
You can simply add in your database a boolean field that will be true/false according to the color selected (for example - if the user chose green - turn the field to ‘true’). On the next page, in the onReady function, simply check the value of the field and adjust the color of the box accordingly.
Hope it helps!
Doron. 