NAT-310: GEANT colors

I cannot manage to run the dockerized GUI properly myself because for some reason the environment variables are not being applied despite being correctly passed.

jorge@jorge03:~$ sudo docker exec -it 8 /bin/sh
/app # echo $REACT_APP_BACKEND_URL
"http://192.168.200.202:3000"
/app # echo $BACKEND_URL
"http://127.0.0.1:8080"

So what I did is, I checked the changes in a local copy of the orchestrator-core-gui repository, and then applied them in the Dockerfile by copying the required CSS files that had to be changed from the original. I built the image to make sure there were no errors. I had to change a bit the suggested color for the text for the case of the dark theme, as otherwise it could be barely read. You can see the looks here: https://jira.software.geant.org/browse/NAT-310

css/colors.ts

+/* Default font colors and table colors */
+export const DARK_FONT_COLOR = "#ffffff";
+export const LIGHT_FONT_COLOR = "#111111";
+export const DARK_ROW_BORDER_COLOR = "#555555";
+export const LIGHT_ROW_BORDER_COLOR = "#cccccc";
+export const DARK_BACKGROUND_COLOR = "#1D1E24";
+export const LIGHT_BACKGROUND_COLOR = "#f6f6f6";
+export const DARK_SELECTED_FONT_COLOR = "#0799fc";
+export const LIGHT_SELECTED_FONT_COLOR = "#0077CCFF";
+
+/* Copy of EUI colors */
+export const PRIMARY_COLOR = "#106C96";
+export const ACCENT = "#274b72";
+export const SUCCESS = "#00bfb3";
+export const WARNING = "#fec514";
+export const DANGER = "#bd271e";
+
+/* Todo: sort remaining colors and investigate if we need them all (we could use `shadeColor()`) */
+export const LIGHTEST_SUCCESS = "#e5ffed";
+export const LIGHT_PRIMARY_COLOR = "#cbe7fb";
+export const LIGHTEST_PRIMARY_COLOR = "#fcfdff";
+export const DARKEST_PRIMARY_COLOR = "#08314bff";
+export const LIGHTER_PRIMARY = "#a8d9e6";
+export const LIGHT_DANGER = "#ffcdc6";
+export const LIGHTEST_DANGER = "#ffddd6";
+export const DARK_SUCCESS_COLOR = "#034b43";
+export const LIGHT_SUCCESS_COLOR = "#d0ffd9";
+export const DARKER_PRIMARY = "#106C96";
+export const GOLD = "#d4af37";
+export const DARK_GOLD_COLOR = "#524217";
+export const LIGHT_WARNING = "#ffe4ab";
+export const LIGHT_GOLD_COLOR = "#fdf6d4";
+export const BACKGROUND_COLOR = "#f9f9f9";
+export const LIGHTEST_GOLD = "#fdfde3";
+export const MEDIUM_GREY_COLOR = "#a6b6be";
+export const DARK_GREY_COLOR = "#565656";
+export const DARKEST_GREY = "#414141";
+export const LIGHT_GREY_COLOR = "#eff2f3";
+export const LIGHTER_GREY_COLOR = "#d9d9d8";
+export const LIGHTEST_GREY = "#fbfbfb";