I wanted the flowers to be grouted white, to help them stand out against the darker background. When grouting with 2 colors you need to grout in 2 sittings. So I taped off the area around the flowers first so the white grout wouldn't bleed into the background.
Once that was done I removed the tape and left it to sit for a bit, then taped off the flowers so they wouldn't collect the darker background grout.
I had some light purple grout left from a different project so I put that on the leaves/lily pads to let them stand out a bit. (Grouting is such a messy process that I usually wait until I have several pieces to do.)
I tried working some light blue and black grouts together on the background, but I didn't like the result so I cleaned most of that off and reworked that area, and the rest of the background in black grout. Now we wait with fingers crossed (and let me tell you it's hard typing with crossed fingers).