Instructions at the bottom of
this page. It's for changing the healer layout to dark colored health and class colored health deficit, but it should be explanatory enough to do the opposite as well. Basically change the "health" indicator color to "class color", and "health deficit" to "health-current". You're literally just swapping the colors on the two indicators.
To get mana to show, open Grid2 options and select your mana indicator. There are options on what it should be showing, make sure Mana is checked. Also, it'll have a color tab, click that tab and make sure Mana is also ticked there (or whatever indicator you want, they all have their own colors you can explore in the statuses section).
If it still doesn't show, disable everything on the indicator then delete it. Remake it, making sure to set the indicator type to bar instead of square or icon, then re-add the Mana stuff.