This pack changes the colour of blocks to show which blocks are potential spawnable spaces for mobs. it uses block-light and not skylight so you can see to light up your outdoor world in the day and it'll be safe at night.
I couldn't find a 1.14 version that worked this way so I made this.
Blocks given a colour are potential spawnable spaces; green for light level 7 and below, till 1 and 0 (blue and purple respectively) which i found useful for showing the next spot to place a light source to get complete coverage with minimal number of light blocks. it also has an additional red band in the nether showing the light levels blaze can spawn at in fortresses (11 and below)

REQUIRES OPTIFINE

I hope this helps makes your worlds a little brighter and safer.