You have a couple of options.
The best results will come from refinishing. Use a paint stripper to expose the wood and take a look at what you have. Paint can hide a lot of defects. Removing the paint and restaining with a gel stain is the best way to get the dark color you are after.
Another option is repainting with a dart tan and applying a gel stain with a wood graining tool. This can be a good option, but is a little difficult to get right. You can experiment on a piece of scrap wood.
It is worth trying the wood graining method. If this doesn't work for you then refinishing is your next option.