So if you wanted to render coloured glass using mia materials in maya and mental ray, you would ( as Master Zap explains here), instead of changing the colour of refraction, tick use max distance in the advanced refraction tab and set the colour here. There are however, two things to consider here. 1. Do not use a fully staurated colour else ull get the same result as simply changing the refraction colour (physically incorrect coloring of glass). 2. Play with the distance parameter, which is scene dependent. At higher values, the colour will attenuate more strongly, moving towards a colourless glass and at lower values, the colour will attenuate less , moving towards fully coloured glass with no attenuation ( as in the extreme case of just changing the refraction colour value).