Just some further questions, and this may well be down to my understanding of the bulbs and binding capabilities, or my expectations may be to high 
- The paring works and I get 2 channels and 2 items.
The color control has Hue, Saturation and Brightness
The Color Temperature Dimmer which maps to the actual 153 - 500 range for the bulb.
However its not possible to change the brightness in white mode, in RGB mode its fine.
My hack was to add a dimmer item to the color channel …
Call it Brightness
And end up with this …
Click on Brightness will turn on white at the selected brightness.
Click on Color Temperature will set the color, but only if light is on
Click the switch on/off will turn on bulb to last setting.
Click on the color square will bring up the color wheel
The Hue is changed by the outer color wheel, the saturation and brightness are changed in the square.
Please let me know if there is a better or cleaner way to do this.
This is the output from zigbee endpoint command
openhab> zigbee endpoint 38251/1
IEEE Address : B4E3F9FFFEFFA288
Network Address : 38251
Endpoint : 1
Device Profile : 0x0104, ZIGBEE_HOME_AUTOMATION
Device Type : 0x010D, EXTENDED_COLOR_LIGHT
Device Version : 1
Input Clusters : (Server)
0000 Basic
- APS Security disabled
S 0 r-- UNSIGNED_8_BIT_INTEGER ZCL Version Tue Feb 15 20:03:33 GMT 2022 3
S 1 r-- UNSIGNED_8_BIT_INTEGER Application Version Tue Feb 15 20:03:33 GMT 2022 65
S 2 r-- UNSIGNED_8_BIT_INTEGER Stack Version Tue Feb 15 20:03:33 GMT 2022 0
S 3 r-- UNSIGNED_8_BIT_INTEGER HW Version Tue Feb 15 20:03:33 GMT 2022 1
S 4 r-- CHARACTER_STRING Manufacturer Name Tue Feb 15 20:03:33 GMT 2022 _TZ3000_qd7hej8u
S 5 r-- CHARACTER_STRING Model Identifier Tue Feb 15 20:03:33 GMT 2022 TS0505B
S 6 r-- CHARACTER_STRING Date Code Tue Feb 15 20:03:33 GMT 2022
S 7 r-- ENUMERATION_8_BIT Power Source
S 8 r-- ENUMERATION_8_BIT Generic Device Class
S 9 r-- ENUMERATION_8_BIT Generic Device Type
S 10 r-- CHARACTER_STRING Product Code
S 11 r-- CHARACTER_STRING Product URL
S 16 rw- CHARACTER_STRING Location Description
S 17 rw- ENUMERATION_8_BIT Physical Environment
S 18 rw- BOOLEAN Device Enabled
S 19 rw- BITMAP_8_BIT Alarm Mask
S 20 rw- BITMAP_8_BIT Disable Local Config
S 16384 r-- CHARACTER_STRING SW Build ID
0003 Identify
- APS Security disabled
S 0 rw- UNSIGNED_16_BIT_INTEGER Identify Time
0004 Groups
- APS Security disabled
S 0 r-- BITMAP_8_BIT Name Support
0005 Scenes
- APS Security disabled
S 0 r-- UNSIGNED_8_BIT_INTEGER Scene Count
S 1 r-- UNSIGNED_8_BIT_INTEGER Current Scene
S 2 r-- UNSIGNED_16_BIT_INTEGER Current Group
S 3 r-- BOOLEAN Scene Valid
S 4 r-- BITMAP_8_BIT Name Support
S 5 r-- IEEE_ADDRESS Last Configured By
0006 On/Off
- APS Security disabled
S 0 r-s BOOLEAN On Off Tue Feb 15 20:36:16 GMT 2022 true
U 16384 r-- BOOLEAN Global Scene Control
U 16385 rw- UNSIGNED_16_BIT_INTEGER On Time
U 16386 rw- UNSIGNED_16_BIT_INTEGER Off Wait Time
U 16387 rw- ENUMERATION_8_BIT Start Up On Off
0008 Level Control
- APS Security disabled
S 0 r-s UNSIGNED_8_BIT_INTEGER Current Level Tue Feb 15 20:36:04 GMT 2022 254
U 1 r-- UNSIGNED_16_BIT_INTEGER Remaining Time
U 2 r-- UNSIGNED_8_BIT_INTEGER Minimum Level
U 3 r-- UNSIGNED_8_BIT_INTEGER Maximum Level
U 4 r-s UNSIGNED_16_BIT_INTEGER Current Frequency
U 5 r-- UNSIGNED_16_BIT_INTEGER Minimum Frequency
U 6 r-- UNSIGNED_16_BIT_INTEGER Maximum Frequency
S 15 r-- BITMAP_8_BIT Options
U 16 rw- UNSIGNED_16_BIT_INTEGER On Off Transition Time
U 17 rw- UNSIGNED_8_BIT_INTEGER On Level
U 18 rw- UNSIGNED_16_BIT_INTEGER On Transition Time
U 19 rw- UNSIGNED_16_BIT_INTEGER Off Transition Time
U 20 rw- UNSIGNED_16_BIT_INTEGER Default Move Rate
U 16384 rw- UNSIGNED_8_BIT_INTEGER Start Up Current Level
0300 Color Control
- APS Security disabled
S 0 r-s UNSIGNED_8_BIT_INTEGER Current Hue Tue Feb 15 20:03:32 GMT 2022 0
S 1 r-s UNSIGNED_8_BIT_INTEGER Current Saturation Tue Feb 15 20:36:04 GMT 2022 254
U 2 r-- UNSIGNED_16_BIT_INTEGER Remaining Time
S 3 r-s UNSIGNED_16_BIT_INTEGER Current X Tue Feb 15 17:49:15 GMT 2022 0
U 4 r-s UNSIGNED_16_BIT_INTEGER Current Y Tue Feb 15 17:49:15 GMT 2022 0
U 5 r-- ENUMERATION_8_BIT Drift Compensation
U 6 r-- CHARACTER_STRING Compensation Text
U 7 r-s UNSIGNED_16_BIT_INTEGER Color Temperature Tue Feb 15 20:36:13 GMT 2022 314
U 8 r-- ENUMERATION_8_BIT Color Mode Tue Feb 15 20:36:13 GMT 2022 2
U 16384 r-s UNSIGNED_16_BIT_INTEGER Enhanced Current Hue
U 16385 r-- ENUMERATION_8_BIT Enhanced Color Mode
U 16386 r-- UNSIGNED_8_BIT_INTEGER Color Loop Active
U 16387 r-- UNSIGNED_8_BIT_INTEGER Color Loop Direction
U 16388 r-- UNSIGNED_16_BIT_INTEGER Color Loop Time
U 16389 r-- UNSIGNED_16_BIT_INTEGER Color Loop Start Hue
U 16390 r-- UNSIGNED_16_BIT_INTEGER Color Loop Stored Hue
U 16394 r-- BITMAP_16_BIT Color Capabilities Fri Feb 11 23:06:10 GMT 2022 25
U 16395 r-- UNSIGNED_16_BIT_INTEGER Color Temperature Min Fri Feb 11 23:08:01 GMT 2022 153
U 16396 r-- UNSIGNED_16_BIT_INTEGER Color Temperature Max Fri Feb 11 23:08:01 GMT 2022 500
1000
- APS Security disabled
Output Clusters : (Client)
000A Time
- APS Security disabled
0019 Ota Upgrade
- APS Security disabled
S 0 r-- IEEE_ADDRESS Upgrade Server ID
S 1 r-- UNSIGNED_32_BIT_INTEGER File Offset
S 2 r-- UNSIGNED_32_BIT_INTEGER Current File Version
S 3 r-- UNSIGNED_16_BIT_INTEGER Current ZigBee Stack Version
S 4 r-- UNSIGNED_32_BIT_INTEGER Downloaded File Version
S 5 r-- UNSIGNED_16_BIT_INTEGER Downloaded ZigBee Stack Version
S 6 r-- ENUMERATION_8_BIT Image Upgrade Status
S 7 r-- UNSIGNED_16_BIT_INTEGER Manufacturer ID
S 8 r-- UNSIGNED_16_BIT_INTEGER Image Type ID
S 9 r-- UNSIGNED_16_BIT_INTEGER Minimum Block Request Period
S 10 r-- UNSIGNED_32_BIT_INTEGER Image Stamp
Groups Configured : 0