Adding Tools to the Toolbox?

[Kloe]

Hi! I'm new to this forum so I appologise if I've put this in the wrong place... ^-^;

I recently updated to 2.10.6 and I realised that some tools aren't on the toolbar anymore. However, they also won't show up in the toolbar preference menu, tools I use a lot like:  Hue-Saturation,  Colorize and  Posterize.

Is there any way to add these back into the toolbar? It seems weird that they wouldn't even be options anymore and is a little inconvinient... 
Thanks in advance! -Kloe♥