Suggestion

I absolutely agree. I think it should be free content but if it was rounded out with accessories, maybe jewellery or make up which we also need, then I'd happily buy it. Plus we need more colour variations, highlights, ombre styles. I'd say my regular hair dye colour is nothing out of the ordinary but it's not there! I mean it's just dark brown with honey tones, it's so common (it was the UK best selling colour)...but it's not there. In Sims 3 my Sims had highlights, I know they won't add a colour wheel to Sims 4 (I think there will be one in Sims 5) but they could still add some more highlighted shades. The ones they have are limited and some aren't great, like the high pony with the block stripes.

I'd like to see more cohesion between regular styles and updos too. I change it up for each outfit category and if you do choose a highlighted style, there isn't a corresponding shade in updos. Or it is an updo and if the Sim has their hair down it has to be a different colour. My Sims with long hair have an updo/pony/braids for the athletic and swimming categories and often an updo for formal wear. Or they have curly or wavy hair and for formal or party wear they have a straightened style or vice versa. 

There's still a way to go with some hair textures too although I know they've improved some over time. But there's one in particular that has coils of hair that are totally flat when your Sim turns to the side. It could look amazing too if it were properly textured.

I think we could use more facial hair choices too. I'd like them to add a few more beard lengths.