Liquid that looks like smoke when bottled?
So you want to make something that looks like smoke. What makes smoke look the way it does, anyway? 

Smoke is composed of extremely fine particles, often below $\mathrm{1\ µm = 0.001\ mm}$ in diameter (check here for comparisons with other particulate materials). These particles are large enough to scatter light, which allows them to be seen, but small enough to be extremely light and stay aloft with even very weak currents in air or liquids.

One interesting and very beautiful consequence of these combined properties is that they can clearly reveal fluid flows, which is what gives smoke its wispy, delicate and complex appearance. That's what fluid flows are like all the time, we just almost never have a direct view of it.

So fundamentally your request is quite simple; all you need is a common, non-toxic source of very fine particulate. Fortunately there are good ways to achieve this in practice. 

One of the most popular seems to be using fine mica dust. These non-toxic silicate minerals can be ground to form tiny, almost perfectly smooth crystalline sheets. When the particles align properly, light is reflected into a viewer's eyes giving a shiny, glittery appearance. If the mica dust is suspending in a liquid, then the many millions of particles twinkle momentarily as they tumble chaotically under the action of currents in the fluid.

Liquid mixtures containing similar materials are called rheoscopic fluids. There are many many sources online for ready-made fluids, or you can make your own from mica powder or other fine solids. Suspensions in water eventually settle, but last for a long time without degradation, needing only a shake to awaken. With a myriad of water-soluble dyes at your disposal, you can adjust the fluid to the desired colour. 

Though rheoscopic fluids based on water and mica are non-toxic and quite safe, that doesn't mean they pose no hazard whatsoever. Very fine particulate can be an irritant if inhaled or exposed to eyes and mucous membranes (especially a problem if handing the dry powder). Just take a bit of care and you can have fun too! Try putting the fluid on a warm surface and see the convection currents!