add missing colors

[Renato-Rodrigues]

Add missing colors for the following variables:

$${\color{#0c0c0c}\blacksquare}$$ PE|Coal
$${\color{#999959}\blacksquare}$$ PE|Gas
$${\color{#005900}\blacksquare}$$ PE|Biomass
$${\color{#0c0c0c}\blacksquare}$$ SE|Electricity|Coal
$${\color{#999959}\blacksquare}$$ SE|Electricity|Gas
$${\color{#005900}\blacksquare}$$ SE|Electricity|Biomass
$${\color{#cccccc}\blacksquare}$$ FE|Non-energy Use
$${\color{#E31A1C}\blacksquare}$$ FE|Transport
$${\color{#5edfff}\blacksquare}$$ FE|Buildings
$${\color{#005900}\blacksquare}$$ FE|AFOFI

[robertpietzcker]

Thanks for adding these missing items!