  We introduce a new spin chain which is a deformation of the Fredkin spin
chain and has a phase transition between bounded and extensive entanglement
entropy scaling. In this chain, spins have a local interaction of three nearest
neighbors. The Hamiltonian is frustration-free and its ground state can be
described analytically as a weighted superposition of Dyck paths. In the purely
spin $1/2$ case, the entanglement entropy obeys an area law: it is bounded from
above by a constant, when the size of the block $n$ increases (and $t>1$). When
a local color degree of freedom is introduced the entanglement entropy
increases linearly with the size of the block (and $t>1$). The entanglement
entropy of half of the chain is tightly bounded by ${ n}\log s$ where $n$ is
the size of the block, and $s$ is the number of colors. Our chain fosters a new
example for a significant boost to entropy and for the existence of the
associated critical rainbow phase where the entanglement entropy scales with
volume that has recently been discovered in Zhang et al. (arXiv:1606.07795)
