Before submitting a map submission make sure you read this first :
https://www.cubecraft.net/threads/map-submission-read-this-before-submitting.219318/
This will explain how to submit your map properly by following the rules of a map submission (adding : poll, creators, Java/bedrock or maybe both)
But about your map, I like the idea of a rainbow in duels but like Lawnti already commented, make the rainbow less triangle to create a more natural view on your map.
Also, your walls are quite boring and definitely need more decoration. Maybe try a different patern?
Maybe you could also create some little hills or maybe even a pot of gold in the middle to make it less empty and to make it look nicer
If there was a Poll I would've voted no, sorry :C