Add colored output support with -c/--color flag

When enabled, colors are applied to:
- Headers: Blue/bold for section titles
- Health status: Green for ✓ (passed), Red for ✗ (failed)
- Temperature: Green (<50°C), Yellow (50-59°C), Red (≥60°C)

Added colorize_health, colorize_temp, and colorize_header helper
functions that respect the USE_COLOR flag.

Fixes: #11

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

driveAtlas.sh

@@ -27,12 +27,14 @@ OPTIONS:
     -v, --version       Show version information
     -d, --debug         Enable debug output (show drive mappings)
     -s, --skip-smart    Skip SMART data collection (faster)
+    -c, --color         Enable colored output
     --no-ceph           Skip Ceph OSD information
     --show-pci          Show PCI paths in output
 
 EXAMPLES:
     $(basename "$0")                  # Normal run with all features
     $(basename "$0") --skip-smart     # Fast run without SMART data
+    $(basename "$0") --color          # Run with colored output
     $(basename "$0") --debug          # Show mapping debug info
 
 ENVIRONMENT VARIABLES:
@@ -48,6 +50,7 @@ EOF
 SKIP_SMART=false
 SKIP_CEPH=false
 SHOW_PCI=false
+USE_COLOR=false
 
 while [[ $# -gt 0 ]]; do
     case "$1" in
@@ -75,6 +78,10 @@ while [[ $# -gt 0 ]]; do
             SHOW_PCI=true
             shift
             ;;
+        -c|--color)
+            USE_COLOR=true
+            shift
+            ;;
         *)
             echo "Unknown option: $1" >&2
             echo "Use --help for usage information." >&2
@@ -83,6 +90,91 @@ while [[ $# -gt 0 ]]; do
     esac
 done
 
+#------------------------------------------------------------------------------
+# Color Definitions
+# ANSI escape codes for terminal colors
+#------------------------------------------------------------------------------
+if [[ "$USE_COLOR" == true ]]; then
+    COLOR_RESET='\033[0m'
+    COLOR_RED='\033[0;31m'
+    COLOR_GREEN='\033[0;32m'
+    COLOR_YELLOW='\033[0;33m'
+    COLOR_BLUE='\033[0;34m'
+    COLOR_CYAN='\033[0;36m'
+    COLOR_BOLD='\033[1m'
+else
+    COLOR_RESET=''
+    COLOR_RED=''
+    COLOR_GREEN=''
+    COLOR_YELLOW=''
+    COLOR_BLUE=''
+    COLOR_CYAN=''
+    COLOR_BOLD=''
+fi
+
+#------------------------------------------------------------------------------
+# colorize_health
+#
+# Returns health indicator with appropriate color
+# Args: $1 - health status (✓ or ✗)
+#------------------------------------------------------------------------------
+colorize_health() {
+    local health="$1"
+    if [[ "$USE_COLOR" == true ]]; then
+        if [[ "$health" == "✓" ]]; then
+            echo -e "${COLOR_GREEN}${health}${COLOR_RESET}"
+        else
+            echo -e "${COLOR_RED}${health}${COLOR_RESET}"
+        fi
+    else
+        echo "$health"
+    fi
+}
+
+#------------------------------------------------------------------------------
+# colorize_temp
+#
+# Returns temperature with color based on value
+# Args: $1 - temperature string (e.g., "45°C")
+#------------------------------------------------------------------------------
+colorize_temp() {
+    local temp_str="$1"
+    local temp_val
+
+    if [[ "$USE_COLOR" != true || "$temp_str" == "-" ]]; then
+        echo "$temp_str"
+        return
+    fi
+
+    # Extract numeric value
+    temp_val="${temp_str%°C}"
+    if [[ "$temp_val" =~ ^[0-9]+$ ]]; then
+        if [[ "$temp_val" -ge 60 ]]; then
+            echo -e "${COLOR_RED}${temp_str}${COLOR_RESET}"
+        elif [[ "$temp_val" -ge 50 ]]; then
+            echo -e "${COLOR_YELLOW}${temp_str}${COLOR_RESET}"
+        else
+            echo -e "${COLOR_GREEN}${temp_str}${COLOR_RESET}"
+        fi
+    else
+        echo "$temp_str"
+    fi
+}
+
+#------------------------------------------------------------------------------
+# colorize_header
+#
+# Returns header text in blue/bold
+# Args: $1 - header text
+#------------------------------------------------------------------------------
+colorize_header() {
+    if [[ "$USE_COLOR" == true ]]; then
+        echo -e "${COLOR_BLUE}${COLOR_BOLD}$1${COLOR_RESET}"
+    else
+        echo "$1"
+    fi
+}
+
 #------------------------------------------------------------------------------
 # Dependency Checks
 # Verifies required commands are available before running
@@ -597,7 +689,8 @@ if [[ "$SKIP_CEPH" != true ]]; then
     build_ceph_cache
 fi
 
-printf "\n=== Drive Details with SMART Status (by Bay Position) ===\n"
+printf "\n"
+echo -e "$(colorize_header '=== Drive Details with SMART Status (by Bay Position) ===')"
 if [[ "$SHOW_PCI" == true ]]; then
     printf "%-5s %-15s %-10s %-8s %-8s %-8s %-30s %-20s %-12s %-10s %-10s %-40s\n" "BAY" "DEVICE" "SIZE" "TYPE" "TEMP" "HEALTH" "MODEL" "SERIAL" "CEPH OSD" "STATUS" "USAGE" "PCI PATH"
     echo "------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------"
@@ -669,11 +762,15 @@ for bay in $all_bays; do
             fi
         fi
 
+        # Apply colors if enabled
+        colored_temp="$(colorize_temp "$temp")"
+        colored_health="$(colorize_health "$health")"
+
         if [[ "$SHOW_PCI" == true ]]; then
             pci_path="${BAY_TO_PCI_PATH[$bay]:-}"
-            printf "%-5s %-15s %-10s %-8s %-8s %-8s %-30s %-20s %-12s %-10s %-10s %-40s\n" "$bay" "/dev/$device" "$size" "$type" "$temp" "$health" "$model" "$serial" "$osd_id" "$ceph_status" "$usage" "$pci_path"
+            printf "%-5s %-15s %-10s %-8s %-8b %-8b %-30s %-20s %-12s %-10s %-10s %-40s\n" "$bay" "/dev/$device" "$size" "$type" "$colored_temp" "$colored_health" "$model" "$serial" "$osd_id" "$ceph_status" "$usage" "$pci_path"
         else
-            printf "%-5s %-15s %-10s %-8s %-8s %-8s %-30s %-20s %-12s %-10s %-10s\n" "$bay" "/dev/$device" "$size" "$type" "$temp" "$health" "$model" "$serial" "$osd_id" "$ceph_status" "$usage"
+            printf "%-5s %-15s %-10s %-8s %-8b %-8b %-30s %-20s %-12s %-10s %-10s\n" "$bay" "/dev/$device" "$size" "$type" "$colored_temp" "$colored_health" "$model" "$serial" "$osd_id" "$ceph_status" "$usage"
         fi
     fi
 done
@@ -690,7 +787,8 @@ if [[ -n "$nvme_devices" ]]; then
     done <<< "$nvme_devices"
 
     if [[ -n "$unmapped_nvme" ]]; then
-        printf "\n=== Unmapped NVMe Drives ===\n"
+        printf "\n"
+        echo -e "$(colorize_header '=== Unmapped NVMe Drives ===')"
         printf "%-15s %-10s %-10s %-40s %-25s\n" "DEVICE" "SIZE" "TYPE" "MODEL" "SERIAL"
         echo "------------------------------------------------------------------------------------------------------"
         echo "$unmapped_nvme" | while read -r name size; do
@@ -714,7 +812,8 @@ fi
 # Ceph RBD Devices
 rbd_devices=$(lsblk -d -n -o NAME,SIZE,TYPE 2>/dev/null | grep "rbd" | sort -V)
 if [ -n "$rbd_devices" ]; then
-    echo -e "\n=== Ceph RBD Devices ==="
+    printf "\n"
+    echo -e "$(colorize_header '=== Ceph RBD Devices ===')"
     printf "%-15s %-10s %-10s %-30s\n" "DEVICE" "SIZE" "TYPE" "MOUNTPOINT"
     echo "------------------------------------------------------------"
     echo "$rbd_devices" | while read -r name size type; do
@@ -727,7 +826,8 @@ fi
 
 # Show mapping diagnostic info if DEBUG is set
 if [[ -n "$DEBUG" ]]; then
-    echo -e "\n=== DEBUG: Drive Mappings ==="
+    printf "\n"
+    echo -e "$(colorize_header '=== DEBUG: Drive Mappings ===')"
     for key in "${!DRIVE_MAP[@]}"; do
         echo "Bay $key: ${DRIVE_MAP[$key]}"
     done | sort -n