The activation of this (amber yellow) "warning" indicates that the engine coolant temperature is high.
It is activated when the temperature reaches 121C (250f).
Note
In this case, stop the vehicle and switch the engine off immediately; make sure that the fans are working.

Low hands free key (hf) battery level
Steering release error - steering still lockedLap registration function
This function describes the "lap" time registration.
If the function is activated (see "lap activation/deactivation
description), the lap time can be registered as follows:
Pressing the flash headlight button (11, fig. 12) The first
time starts the "lap timer" for ...
Lcd unit functions
Speedometer.
Gives road speed.
Rev counter.
Indicates engine revs per minute.
Clock.
Water temperature indicator.
Indicates engine coolant temperature.
Important
Stop riding if the temperature reaches the maximum
value, otherwise the engine might be damaged.
...
Oil pump
Complete oil pump assembly
O-ring
Circlip
O-ring
Pump body
Circlip
Reducer bush
Spring washer
Screw
Screw
Spring washer
Pump drive gear
Key
By-pass plug
Locating bush
By-pass spring
By-pass valve
Spare parts catalogue
Diavel abs filters and oil pump
Diavel ...