Shell script to generate random hex numbers

I need some help in the shell script. Here is a code I am using to edit image filters where I am using hex colors along with white color. Now I need to make random hex color so that the code will generate a new image every time the code runs. I am able to do it by specific hex color codes. Here is the code for that : ``` STRING="Freddy script converts an image into a different style" echo $STRING arg=$1 filename=(${arg//./ }) echo $filename ./freddy/popart -r 1 -c 1 -g 0 -i bilinear -c1 "#FF0000 white" $1 output-beta/$filename-popart1.png ``` In the above code popart is the image filter script and output-beta is the folder where the popart1.png will be saved. I need to make random hex codes in place of "#FF0000". Please help.