diff --git a/Dockerfile b/Dockerfile
index ab01909..53f8096 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,46 +1,31 @@
-# Use an official Node.js runtime as a parent image
 FROM node:slim
 
-# Define default values for environment variables
-ARG APP_TITLE="STAC Manager"
-ARG APP_DESCRIPTION="A web application for managing STAC catalogs"
-ARG REACT_APP_STAC_API="https://earth-search.aws.element84.com/v0"
-ARG REACT_APP_STAC_BROWSER="https://radiantearth.github.io/stac-browser"
-ARG PUBLIC_URL="http://127.0.0.1:8080"
-ENV REACT_APP_KEYCLOAK_URL=
-ENV REACT_APP_KEYCLOAK_CLIENT_ID=
-ENV REACT_APP_KEYCLOAK_REALM=
-
-ENV APP_TITLE=${APP_TITLE}
-ENV APP_DESCRIPTION=${APP_DESCRIPTION}
-ENV REACT_APP_STAC_API=${REACT_APP_STAC_API}
-ENV REACT_APP_STAC_BROWSER=${REACT_APP_STAC_BROWSER}
-ENV PUBLIC_URL=${PUBLIC_URL}
-ENV REACT_APP_KEYCLOAK_URL=${REACT_APP_KEYCLOAK_URL}
-ENV REACT_APP_KEYCLOAK_CLIENT_ID=${REACT_APP_KEYCLOAK_CLIENT_ID}
-ENV REACT_APP_KEYCLOAK_REALM=${REACT_APP_KEYCLOAK_REALM}
-
-# Set the working directory
+ARG APP_TITLE=%APP_TITLE%
+ARG APP_DESCRIPTION=%APP_DESCRIPTION%
+ARG PUBLIC_URL=%PUBLIC_URL%
+ARG REACT_APP_STAC_API=%REACT_APP_STAC_API%
+ARG REACT_APP_STAC_BROWSER=%REACT_APP_STAC_BROWSER%
+ARG REACT_APP_KEYCLOAK_URL=%REACT_APP_KEYCLOAK_URL%
+ARG REACT_APP_KEYCLOAK_CLIENT_ID=%REACT_APP_KEYCLOAK_CLIENT_ID%
+ARG REACT_APP_KEYCLOAK_REALM=%REACT_APP_KEYCLOAK_REALM%
+ARG REACT_APP_THEME_PRIMARY_COLOR=%REACT_APP_THEME_PRIMARY_COLOR%
+ARG REACT_APP_THEME_SECONDARY_COLOR=%REACT_APP_THEME_SECONDARY_COLOR%
+
 WORKDIR /app
 
-# Copy the rest of the application code
 COPY . .
 
-# Install dependencies
 RUN npm i
 RUN npm i -g http-server
+RUN npm run all:build
+RUN cp -v packages/client/dist/index.html packages/client/dist/404.html
 
-# Create a start script that respects runtime environment variables
-RUN echo '#!/bin/sh\n\
-echo "Starting build"\n\
-npm run all:build\n\
-echo "App built successfully"\n\
-cp -v packages/client/dist/index.html packages/client/dist/404.html\n\
-echo "Starting server"\n\
-http-server -p 80 packages/client/dist' > /app/start.sh
+RUN apt-get update && apt-get install -y gettext-base sed
 
-RUN chmod +x /app/start.sh
+COPY docker-entrypoint.sh /app/docker-entrypoint.sh
+RUN chmod +x /app/docker-entrypoint.sh
 
 EXPOSE 80
 
-ENTRYPOINT ["/app/start.sh"]
+ENTRYPOINT ["/app/docker-entrypoint.sh"]
+CMD ["http-server", "-p", "80", "packages/client/dist"]
diff --git a/docker-entrypoint.sh b/docker-entrypoint.sh
new file mode 100644
index 0000000..262c194
--- /dev/null
+++ b/docker-entrypoint.sh
@@ -0,0 +1,22 @@
+#!/bin/sh
+set -e
+
+echo "Startup script"
+echo "Replacing environment variables in built files..."
+
+# Replace placeholders with env vars or defaults only in the built files
+find /app/packages/client/dist -type f \( -name "*.html" -o -name "*.js" -o -name "*.css" -o -name "*.map" -o -name "*.json" \) | xargs sed -i \
+  -e "s|%APP_TITLE%|${APP_TITLE:-STAC Manager}|g" \
+  -e "s|%APP_DESCRIPTION%|${APP_DESCRIPTION:-A web application for managing STAC catalogs}|g" \
+  -e "s|%PUBLIC_URL%|${PUBLIC_URL:-http://127.0.0.1:8080}|g" \
+  -e "s|%REACT_APP_STAC_API%|${REACT_APP_STAC_API:-https://earth-search.aws.element84.com/v0}|g" \
+  -e "s|%REACT_APP_STAC_BROWSER%|${REACT_APP_STAC_BROWSER:-https://radiantearth.github.io/stac-browser/#/external/$(echo ${REACT_APP_STAC_API:-earth-search.aws.element84.com/v0} | sed 's|^https://||')}|g" \
+  -e "s|%REACT_APP_KEYCLOAK_URL%|${REACT_APP_KEYCLOAK_URL:-}|g" \
+  -e "s|%REACT_APP_KEYCLOAK_CLIENT_ID%|${REACT_APP_KEYCLOAK_CLIENT_ID:-}|g" \
+  -e "s|%REACT_APP_KEYCLOAK_REALM%|${REACT_APP_KEYCLOAK_REALM:-}|g" \
+  -e "s|%REACT_APP_THEME_PRIMARY_COLOR%|${REACT_APP_THEME_PRIMARY_COLOR:-#6A5ACD}|g" \
+  -e "s|%REACT_APP_THEME_SECONDARY_COLOR%|${REACT_APP_THEME_SECONDARY_COLOR:-#048A81}|g"
+
+echo "Environment variable replacement complete"
+
+exec "$@"