Late to the conversation, but yes some commercial pale lagers are much darker than they taste (and Modelo is the most noteable one I can think of). For comparison, I currently have a beer on tap that is 2/3 Vienna malt and 1/3 Flaked corn. The color is light straw, not even close to gold. I brew several beers a year that are a riff on this grain bill and none come even close to Modelo Especial (let alone Negra Modelo, which many are probably closer to in flavor). While it wouldn't surprise me than many craft breweries are using something grain-based like Sinamar, Carafa Special, Midnight Wheat, etc., I'd be willing to bet that the big boys just use caramel color.
I've used brewer's caramel before, and it's easy to use and completely flavorless. You can turn a pale beer inky black if you want and it tastes no different. I stopped making color adjustments to my beer a while ago because I generally don't care, but if it were available in the US, I wouldn't think twice about keeping some brewer's caramel on hand to tweak the color of my brews when warranted.