This is extremely busy - I think removing the stuff from the date boxes and perhaps cleaning up the design in the background would go a long way towards making it more readable.

I like how you did a lot of icons in the date boxes, however I do not like the anthropomorphic animal.

First off, you don't need to reply 3 times to your own artwork. You can edit your posts.

I've highlighted the extra colours in eye-burning green (so you won't miss them!)

Most of the extra colours are very similar to other colours. You also have black, which isn't listed in your palette.

I recommend downloading irfanview. It's an image viewer which also includes an inbuilt colour counter (Image > Information). The program is free and the file size is tiny.

Despite the palette you've placed at the bottom, this one actually has 28 colours =/