I must admit I have to think very carefully about these three.

Palate:

• the roof of the mouth
• the sense of taste or ability to distinguish between and appreciate flavours
• the flavour of wine and beer

Palette:

• a flat, thin board used by artists to mix paints
• the range of colours characteristic of a particular artist or school of painting, also the range of colours used in a particular painting
• the range of colours, patterns or shapes that can be displayed on the visual display unit of a computer
• the range of tonal colour in a piece of music

Pallet:

• a straw-filled mattress or bed; a crude, temporary or makeshift bed
• a tool (often wooden) with a flat blade used for shaping clay or plaster
• a portable platform for stacking, storing and moving goods
• a projection on a machine part that changes the motion of a wheel

Pallet also has specialist uses in relation to timepieces and heraldry.