Thanks for the example code for this sensor (SEN-12829). I put a small piece of wood over the sensor into which a cardboard straw could be inserted, with an RGB LED on top. This helped reduce color count variations. So did changing the delay(300) to delay(400) in the example code (ISL29125RGBLED.ino). The color counts are now very consistent ±2. The picture also shows using the Logic Level Converter - Bi Directional. A fun project. All done on that almost-no-longer-available STEMTera breadboard.
Awesome!