WSJT-X waterfall help.

I'm fairly new to FT8 mode and WSJT-X. If I understand correctly the waterfall is showing the receiving signal strength in my location. Should I avoid transmitting/or receiving in the edges of the band due to excess noise levels? Also, will tx/rx in the darker areas of this graph give me a better chance of decoding signals? Thanks for any help given.

https://preview.redd.it/1w4ehf6ioooe1.jpg?width=1920&format=pjpg&auto=webp&s=f9863dff3c5b30ef456cdcb0b2167dc113cfd448