Best leather darkening oil?

[MatHalTed]

Bought a new chin strap for one of my western headstalls and on the website it looked a pretty good colour match, however it's arrived now and the leather is significantly lighter. I've given it a go over with the leather conditioner I have on hand and it's darkened slightly but still not a good colour match. Basically looking for recommendations for any good leather darkeners. Headstall is a dark chestnut colour. Will attach a pic for reference

 

[YourValentine]

Hydrophane is excellent for darkening leather

 

[sbloom]

Pure neatsfoot is one of the best oils to use on leather and it darkens significantly in most cases. Fiebings has a range of products including actual dyes but also possibly some tinted products.