Stain and Re-Stain
Choose a desired color for the wood, most likely matching the original color. Make sure the surface is dust free, then apply a coat of stain in this color. Let it dry, then apply another coat of stain. Depending on how it looks after this second coat, you can continue to apply coats until you're pleased with the outcome.
Read the instructions that come with the stain, and follow them if they differ from what's presented here.