Blue and yellow make green in a paint box and white-ish grey on a screen. The answer depends on what is being mixed, so choose that first.
A simulation of opaque pigment using Kubelka-Munk theory on an assumed reflectance curve. It shows how pigments tend to behave, and it cannot predict a real paint.
Nearest named colour: Teal #008080, ΔE00 4.8
Searches the colours above for the mixture closest to a target. The colours you have listed are what it can use, which is the question a real paint box asks.
Use paint mode to plan a mix before opening the tubes, or to understand why a mix turned muddy. Use light mode for stage lighting and overlapping screens, and digital modes for CSS, where the numbers are what matter.
Paint mode is a simulation made from a screen colour. A real pigment has a spectrum, a strength and an opacity that a HEX code does not record, so two paints that look identical can mix differently. Phthalo blue is far stronger than ultramarine, part for part, and this tool cannot know that.
Binder, gloss, drying and the surface underneath change the result again. It does not know any paint brand, and no result here is a brand equivalent. Mix a small test before committing.
Paint mode builds a plausible reflectance curve for each colour across 36 wavelengths and mixes absorption and scattering by proportion, using a single-constant Kubelka-Munk model. That is why blue and yellow go green here and not grey. Light mode adds linear-light energy, the way overlapping lamps do. Digital mode averages sRGB values like a basic CSS mix, and perceptual mode averages in OKLab.
The target search tries combinations of your colours at the chosen precision and scores each with CIEDE2000. It stops at a fixed number of candidates so that it stays quick, and it tells you if that made it search more coarsely.
For fixed colour pairs, the mixing guides explain why particular mixes behave the way they do.