The present invention relates to a compound of formula (I-0) or a salt thereof. The invention further relates to the use of such compound as a colouring agent. The invention also relates to a colouring composition comprising such compound.

The present invention relates to a compound of formula (I-0) or a salt thereof. The invention further relates to the use of such compound as a colouring agent. The invention also relates to a colouring composition comprising such compound.

Electrowetting apparatus including at least one compound selected from the group consisting of: ##STR00001##
wherein each of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 is independently an alkyl group. In examples a fluid includes a dye compound selected from: ##STR00002##

An anthraquinone compound is provided. The anthraquinone compound has the following formula (I):

##STR00001## wherein one of R.sub.1, R.sub.2, and R.sub.3 is NH(CH.sub.2).sub.mCH.sub.3, and the other two are each independently selected from hydrogen or C.sub.1-4 alkyl group; and n and m are each independently an integer from 4 to 17.

This invention relates to electrophoretic fluids comprising a solvent, a dye, white particles, and colored particles selected from red, green, blue, magenta, cyan, yellow particles, and mixtures thereof, and electrophoretic display devices comprising such fluids.