Cook's Blue vs RAL 650-1
Cook's Blue is a Farrow & Ball color while RAL 650-1 comes from RAL Effect. These are both blues, so the question isn't which hue to choose — it's where within blue to land. At LRV 36 vs 25, RAL 650-1 will read as the brighter of the two — a 10-point gap that matters most in north-facing or low-light rooms. At ΔE 16.7, these are genuinely distinct colors — a strong contrast if used together, or a meaningful choice between two different directions. Below you'll find 5 real-room photo comparisons where both colors appear side by side, plus 5 simulated room previews.
Cook's Blue vs RAL 650-1 in Real Spaces
5 real rooms side by side. Seeing Cook's Blue and RAL 650-1 in actual rooms makes the difference concrete; browse the spaces below to get a feel for how each color lives on a wall.
Living Room
Living rooms test a color across a full range of conditions — morning sun, afternoon shade, and evening lamp light all shift how both of these read. RAL 650-1 returns significantly more light to the room — in a smaller or darker space, that difference in perceived brightness is hard to miss.
Bedroom
Bedroom walls are often seen under warm artificial light, a context that shifts both colors from how they look on a chip. The LRV gap is large enough that RAL 650-1 will make the room feel meaningfully brighter than Cook's Blue would.
Bathroom
Bathrooms amplify color — the enclosed space and reflective surfaces make what reads subtle elsewhere feel more present here. The LRV gap is large enough that RAL 650-1 will make the room feel meaningfully brighter than Cook's Blue would.
House
At full exterior scale, the difference between these two colors becomes much easier to judge than from a small chip. The LRV gap is large enough that RAL 650-1 will make the room feel meaningfully brighter than Cook's Blue would.
Kitchen Cabinets
On cabinetry, undertone and temperature become more pronounced against countertops and hardware. The LRV gap is large enough that RAL 650-1 will make the room feel meaningfully brighter than Cook's Blue would.
Color Details
Cook's Blue vs RAL 650-1 Simulated Comparison
5 simulated room previews — drag the slider on each to see Cook's Blue on one side and RAL 650-1 on the other.
Digital color is approximate. These simulations are generated from the manufacturer's hex values and overlaid on grayscale room photos — your screen's calibration, brightness, and viewing angle all affect how they render. Before committing to either color, test physical samples in your own space under the light you actually live with.
More Cook's Blue comparisons
See how Cook's Blue stacks up against other well-photographed colors across different brands and tones.
