Sprint has announced that it's going to start offering the HTC One (http://www.gsmarena.com/htc_one-5313.php) in a red color. Dubbed "Ruby Red", the special color of the HTC One is going to be exclusive for Sprint customers in the US.
HTC has already started selling (http://www.gsmarena.com/htc_one_in_glamour_red_hits_uk_in_the_coming_month-news-6287.php) the One in red in the UK and is calling the paint job "Glamour Red." That's the reason for the slight difference in saturation you're noticing.
The HTC One is also expected to be available in a blue color (http://www.gsmarena.com/htc_one_to_be_available_in_red_and_blue_versions_-news-6116.php) variation, a photo of which (http://www.gsmarena.com/blue_htc_one_photo_makes_its_first_online_appearance-news-6529.php) leaked not too long ago. Any further information regarding its availability or pricing are not available at this point.
Anyway, back to the Sprint Ruby Red HTC One edition, it's going to be available starting August 16 for $199,99 (the same price of the regular graphite and silver HTC One) with a 2-year contract. Off-contract, the device is going to retail for $549.99. Sprint is also throwing in a promo offering for a chance to win a second HTC One if you buy one.
Via (http://www.androidpolice.com/2013/08/15/sprint-gets-exclusive-red-htc-one-starting-august-16th-buy-one-get-one-free-promotion-as-well/)
GSMArena.com