White (but a tad yellowish once misted and under the light), but white and flat-ish (not fluffy-ish). I have a fabric under it (light table cloth material - I have a lot of it and can just throw it away when cleaning tanks) that may be adding to/affecting the appearance? These are hardly words, I know, but it is the best I can do for explaining!

No really, I am just about certain I had it wrong. You know "avoid ceder and pine" was on my mind when looking to change substrate, so when writing about it part of the mantra came out instead of the correct word.