Unable to change colours of objects in Illustrator

[Ethereal_enthusiasm5C11]

As you can see, here's one example of one object I'm unable to change to colour. 

I've changed the color options from "grayscale" to "CMYK", to choose what colors I want but when I select the desired color nothing happens.
I've selected the object and expand, and still nothing happens.

I've reset the settings to default and redo the above steps but nothing happens.

Anyone have this issue before?

[Mike_Gondek]

There are many reasons, but you can narrow them down if you select the item, and show the appearance palette

• The item might have transparency set to multiply.
• You may have a fill at the group level or even layer level set to black.

Copy and paste it to the side, does the red show?

[Monika Gause]

When you open the color panel and show its options, what do you see?