You're overcomplicating it, getting lost in the detail.

Those spots aren't everywhere, they are mainly just on the head so you don't need to put them on the tentacles and you should consider that if something goes on a tentacle, it'll also go on the arms and legs.
The bright goes down to the tentacles so why not make the face that color and keep it consistent until it reaches a limb?
Drop that spraycan and never pick it up again. There is no use for it pretty much ever.
Try picking up a bigger brush instead and block things out and recycle colors.
Don't use new ones for every new object or the picture will not look unified at all and be hard to edit.
