Color fires from ember to white-hot instead of blue to red

About 90% of detections are under 20 MW, so the old blue and teal
stops painted most of the map in cold colors that do not read as fire.
The ramp now runs ember, red, flame, orange, gold and white-hot at the
same thresholds, each stop lighter than the one below, so the brightest
marks are the strongest fires. The heatmap uses the same colors.

docs/CURRENT-STATE.md

@@ -2175,19 +2175,22 @@ accessible name remains "Don't show this again". Control behavior is unchanged.
 
 ## Active Fires intensity filter and color ramp
 
-Every FIRMS detection is colored by fire radiative power on a six-stop cold →
-hot ramp: blue from 0 MW, teal from 5, lime from 20, amber from 50, orange from
-100 and red from 300 MW (`FRP_RAMP` in `src/data/firmsIntensity.js`). Glow
-sprites and fire-card accents read that ramp; confidence and brightness do
-not affect the color.
+Every FIRMS detection is colored by fire radiative power on a six-stop ember →
+white-hot ramp: dark ember from 0 MW, red from 5, flame from 20, orange from
+50, gold from 100 and pale white-hot from 300 MW (`FRP_RAMP` in
+`src/data/firmsIntensity.js`). Each stop is lighter than the one below and
+none is a cold hue, so the brightest marks are the strongest fires; ~90% of
+detections are under 20 MW and stay dim red. Glow sprites and fire-card
+accents read that ramp; confidence and brightness do not affect the color.
 
 At far zoom (camera above ~3,000 km) the layer drapes a Snap Map–style
 heatmap instead of individual markers: the shown detections are binned on a
 global 2048 × 1024 grid, each weighted by its FRP in megawatts (so heat is
 radiated power, and raising the FRP slider does not dim areas where strong fires
 burn), Gaussian-blurred,
-normalized on a log scale against the 99.5th percentile and mapped from blue
-through cyan, green, yellow and orange to red. Nothing is painted where
+normalized on a log scale against the 99.5th percentile and mapped through the
+same colors, from a faint ember edge through red, orange and gold to a pale
+white-hot core. Nothing is painted where
 nothing burns (`src/data/firmsHeatRaster.js`). It is one full-globe imagery
 tile on the active imagery host (`src/layers/firms/heatImagery.js`), rebuilt
 on each data refresh or filter change (the first paint at once, later ones