Twan Leenders, biologist and author of the Guide to the Amphibians and Reptiles of Costa Rica and some other books on reptiles and amphibians in Costa Rica, helped me identifying this species.
This species was recently moved into the genus Holcosus; it was formerly known as Ameiva festiva.
The one on the photo is a juvenile. The beautiful blue tail and red and yellow pattern disappears as they grow older. Older individuals often only have a light stripe running over their back.
Old Buenavista Road, Anchicaya area, Valle del Cauca, Colombia, 14 June 2016