No hotkey for laptops

I have a number pad on my Gaming Laptop (not the numbers above the letters the number pad on the right of the keyboard where Number Lock is next to your Arrow Keys) and to the right of NUMLK there's the - and + keys both you can use to go through the colours of the objects. To use Page Down and Page Up you have to hold Shift since it's on the number pad on Laptops so if you press it you're just pressing the numbers personally i'm up with just clicking the icon at the top of the game.