Low optical-crosstalk color pixel scheme with wave-guiding structures is demonstrated in a high resolution CMOS image sensor with a 0.8um pixel pitch. The high and low refractive index configuration provides a good confinement of light waves in different color channels in a quad Bayer color filter array. The measurement result of this back-side illuminated (BSI) device exhibits a significant lower color crosstalk with enhanced SNR performance, while the better angular response and higher angular selectivity of phase detection pixels also show the suitability to a new generation of small pixels for CMOS image sensors.