Before we talk colors, I ask whether this is a patio, a path or a driveway, because the color method should match the traffic. A patio that gets chairs and bare feet does fine with integral color. A driveway with tires turning on it every day usually does better with the tougher surface color hardener gives.
A decorative top can't hide a weak base, so the base gets the same care as the color. We dig out and pack the subgrade, the soil the slab sits on, pour the thickness the use calls for and set rebar, steel bars that hold the slab together if it cracks, sized to the job. We also check where the water runs so the slab falls away from your house.
We plan the pour so finishing doesn't land in the hottest part of the day, because a top that dries too fast turns weak and dusty later. Control joints are shallow cuts that give the slab a planned place to crack, and we cut them on time so any cracks follow lines we chose instead of wandering across your pattern.
When a budget gets tight, the base is the first thing people want to trim, because nobody sees it on day one. I'd rather you pick a simpler pattern than skimp underneath, since a nice finish on dirt that was only raked level settles right along with the dirt. That's what I learned fixing other people's sunken slabs.
Some yards need work before the decorative slab goes in. If the spot slopes, a concrete retaining wall can hold the soil back and give you a level place for the patio. If what you really want is a solid slab inside a garage or shop, that's concrete floor installation, which we plan for indoor use.