Rock identification - dingle

Hi Geology people.

hoping ye can help and maybe explain what im seeing.

All three are from the Dingle Peninsula.

Mountain, Range, MointainViews.ie description

1. Gearhane, Slieve Mish, Purple Cross-bedded Sandstone
2. Croaghskearda, Central Dingle, Purple Cross-bedded Sandstone
3. Caherconree Fort, Slieve Mish, Aeolian Sandstone

01, was definitely the most colourful I've seen over the last year. Is it the rock, something growing on it, or some sort of shell /crystallisation(sorry for the really poor description) on it?

02, similar to 1 i guess. what are the blue/grey/silver patches on it?

03, its from the fort wall, is it the aeolian sandstone, most of the rock around had the same shape but the colour of this one obviously stood out.

The tops of these mountains have loads of different types, to my eyes at least, and i'm no nearer to understanding what I'm looking at.

also, maybe , could ye recommend anything to read up that wouldn't be too academic :)

thanks ahead of time