If you have lightened your hair and want to return to your natural colour the process is less complicated and a lot less damaging to your hair. There are also a couple of ways of returning back to your natural colour after lightening.
You can let the colour grow out again and have regular trims. With going back darker a semi permanenet colour would be applied so it would not damage the hair so that rule doesnt apply when going darker.
If you choose to put a semi permanent colour close to your own colour on make sure you add warmth if you dont when the colour fades it will go a khaki colour and we dont want that.
When we lighten our hair natural tones are removed so when returing back darker they need to be replaced. If you are going back to a dark blonde shade, golden tones need to be added to colour you desire. if a medium brown is desired copper needs to be added. If a dark brown or back wants to be acieved red needs to be added. Only apply teh colour where the lightened pieces are also have regular trims aiding the process. Let the colour grow out and putting the semi on will diguise the change going on.
We may believe that our stylist can work wonders and ususally they can transform any issue that occurs with hairstyles and colours. But making the decision to change the colour of the hair is not such an easy option. I would consider a good consultation with your stylist should allow you to make a decision on changing the colour of your hair with confidence.