I'm following a beginner's tutorial where I am supposed to colour a skull that has different symbols on it. It was going all fine until I had to select the yellow bits to add different colours to the skull, but Illustrator won't select it if I click on it, only the outline. I have to specifically go to the layers panel and meatball the path I want to colour, which is really annoying and time consuming. What should I do to active the selection by a click? 

[![the area selected and coloured is what I want to achieve just by clicking on it but it doesn't work, only from the layers panel][1]][1]


  [1]: https://i.sstatic.net/2nlrK.png