A method of detecting an analyte is provided. The method includes providing a sample, a container 110 with a wall 115, and a catalyst for a luminescent reaction. The wall includes a colored portion 115b. The method further comprises forming a reaction in the container and detecting the presence or absence of light emitted from the reaction mixture in the container. Detecting light emitted from the container can comprise detecting light passing through the colored portion. The colored portion can be detected visually and the color can be associated with the identity of an analyte—specific reagent disposed in the container. Kits comprising the container and a catalyst for a luminescent reaction are also provided.