Eagle made some all leather gloves (many in a natural brown) a few years ago, not sure if they are currently making any. If not, could try ebay, craigslist, kijiji, etc. for a used pair
I got a barely used pair of Eagle H34 gloves - my pair is black, but they also came in the natural tan. I think mine are made of goat skin, but I read in a forum that they used horse when they first came out until some people complained. H35 is the same glove but in a longer cuff. A more recent model is the G70 (goat) and L70 (leather).
Other models came in all leather - the L30 I think; not sure if come in the natural brown.