Project hail mary and Yellow
In phm yellow seems to symbolise hope. Some examples of this are: the bright yellow jump suits of the crew, the yellow lighting in SO MANY scenes of hope.
For the lighting in many scenes such as when Grace first starts to communicate with Rocky in the tunnel the entire scene is tinted yellow by the lights. Or in other scenes such as when Rocky says he will give Grace the astrophage to get home the entire screen is dark with the yellow light slowly appearing silhouetting Rylands dark form before he steps into the light. In scenes of Adrian there is a mix of green and yellow and in moments where it seems they have failed it instead switches to pure green. For example after Grace gets back in the ship and they try to leave orbit the entire control room is tinted green and when Grace passes out we see Rocky and him from each other's perspectives both back-lit with a yellow light.
When grace wakes up afterwards the lighting is a warm yellow but upon seeing Rocky's body it shifts to a much cooler white.
Other instances of yellow include: many later Grace on earth scenes, the beetles sealed with yellow tape, Grace's video being warm toned in contrast to Stratt at the end, Grace's habitat on erid.
