One of the descriptions of what makes a glass opalescent is that when backlighted it shows as an orange color. This glass is usually a whitish to a whitish with a blue tint to a light blue.There are tons of variations Bo's marble may be a nice greyish opalescent glass. Probablyly Though, the red ribbons reach to the center of the marble imparting the red glow(very common on rainbos). Not a red base IMO. And being a charter member of NHA I will let you all play the name game. Peace,Galen