No two pieces of wood are identical which makes each component unique. Colours change overtime and gain a more uniform colour, the speed of this process depends on the wood specie, surface treatment and the extend of light it is exposed to. Do not expose solid wood and veneers to excessive sunlight. Solid wood and veneers differ from specie to specie and batch to batch.
Some solid woods and veneers may have more distinctive grain than others due to the wood being harvest from different trees in different regions and forests with different climates. These factors will result in each component having its own unique characteristics in term of appearance and aging.