TAOSINC which is a division of Texas Instruments has their own line of devices which specialize in light sensing or light to voltage conversion.

TCS230 – 4-Channel Light to Frequency
TSLB257 - Blue light to voltage converter
TSLG257 – Green light to voltage converter
TSLR257 – Red light to voltage converter

A qoute from the TAOSINC RGB LTV sensor page:

“The integrated color LTV sensors combine a photodiode, color filter, and transimpedance amplifier on a single die. The output is then fed to an ADC for digital processing. TAOS’ solution requires fewer components, saves board space and reduces assembly cost over a discrete photodiode approach. TAOS’ solution also simplifies design and board layout because sensitive analog circuitry is integrated on-chip, which also improves the noise immunity. The Color LTV devices are ideal for applications such as colorimetry, printing process control, display color correction, and selectively ambient light detection or rejection. ”