I took a look through your video. Another tip: watch tutorials to your own expense. Sometimes they can be overpowering and difficult for new learners, however they are still great resources.
I noticed in the video that:
tagColor.Value = Color3.fromRGB(255,255,255)
was not a Color3 value. It was instead a BrickColor. Try changing this to:
tagColor.Value = BrickColor.new("Really black")
If there are any other issues, make sure to go back into the video for help. The correct script is already prewritten so I don’t understand the need to ask the DevForum.
Color3 can be used to obtain a wide array of colors, while BrickColor only uses preset colors. Some functions in Roblox can only use BrickColor instead of Color3. I don’t know the exact reason behind it, but my guess is that it doesn’t have to do guessing work for each color.