That is D. auratus. (4th frog) The 3rd frog is D. tinctorius.
Dendrobates auratus Morphguide
http://www.tropical-experience.nl/index.php?option=com_content&view=article&id=62&Itemid=49&lang=en
Look through here and match it up, or maybe find something similar that you like more!
Here is a link to my Tincs... But they are yellow, blue and black...
http://www.dendroboard.com/forum/members-frogs-vivariums/60468-tinc-pics-suriname-cobalt.html
JBear
Dendrobates auratus Morphguide
http://www.tropical-experience.nl/index.php?option=com_content&view=article&id=62&Itemid=49&lang=en
Look through here and match it up, or maybe find something similar that you like more!
Here is a link to my Tincs... But they are yellow, blue and black...
http://www.dendroboard.com/forum/members-frogs-vivariums/60468-tinc-pics-suriname-cobalt.html
JBear