At concerts and live performances, the timing for changing the color of the penlight is roughly determined by the song. Many audience members are unaware of this, and some change the color while looking at their surroundings, while others do not use penlights because they do not have the confidence to match the color. In this research, we thought that if there were a penlight that changed color to match the surroundings by pressing a button when the user wanted to change the color, the user could enjoy the fun of changing the color by themselves while concentrating on the concert. We created a penlight that recognizes the color of the surrounding environment and automatically changes color when the button is pressed, and had people use it to see if they could concentrate on the screen.