Background: The loss of teeth from one's mouth will increase the need for dentures. The denture base used was heat-cured acrylic resin, in Indonesia. Many natural products are offered to the community where these products have many benefits for the body, one of which is rosella flower tea. Rosella flower tea contains natural dyes, anthocyanins, if consumed regularly it can cause discoloration on the acrylic resin plate. Aim: This study was to determine the effect of immersing heat-cured acrylic resin in a solution of rosella flower tea (Hibiscus sabdariffa L.) on discoloration. Material and method: Experimental study with control group pre-test and post-test design. The samples were heat cured acrylic resin plate with N number was 32 and divided into 2 groups, the control groups and the treatment groups. The control group (16 samples) was immersed in distilled water and the treatment groups (16 samples) was immersed in rosella flower tea solution. First, all of the samples 32 samples were immersed for 7 days, dried and performed color changed measurement, then immersed again for additional 7 days, dried and performed color changed measurement. Color changes were measured using the VITA Easyshade device both before and after 7 and after additional 7 days of immersion. Results: The result of the Friedman test showed significant color changes in acrylic resin plates in treatment group, especially on the value of chrome. The result of the Mann Whitney test showed that they were significant differences in the heat acrylic resin plate after immersions in distilled water solution and rosella flower tea for 7 days, and after additional 7 days especially in the chrome. Conclusions: Immersing heat cured acrylic plates in rosella flower tea has color changes effect, the longer the immersion time, the greater the potential the color changes