I'm having an issue with Paint Tool Sai. If I'm pressing

Depends on what kind of tablet you have.

I use a super old Bamboo Waocm Fun and Touch .There's a white button on the side of the pen that when I press goes to the colour picker.

Try uninstalling and reinstalling the tablet? Or updating drivers?

is the color picker right click? if so there is an anoying preset in windows that right clicks when youre holding down. dumb, i know
http://www.volnapc.com/all-posts/how-to-get-rid-of-those-annoying-circles-from-your-wacom-cursor-in-windows-7

>>3065316
>http://www.volnapc.com/all-posts/how-to-get-rid-of-those-annoying-circles-from-your-wacom-cursor-in-windows-7

omg that's what's been happening all this time!

>>3065315
I'm drawing on a Microsoft Surface with Windows 10. I probably should have specified that.

>>3065316
On the pen, the right click button is the color picker. I've tried to change it using the "digitize support" menu but it doesn't work even though it says it was changed.

>>3065316
Thanks for the link! I was able to fix it.
Turns out I have the circle 1 issue.