diff --git a/REQUIRE b/REQUIRE
index 2034ee8..a1bcf3f 100644
--- a/REQUIRE
+++ b/REQUIRE
@@ -1,6 +1,6 @@
 julia 0.6
 Colors 0.7.1
-ColorTypes 0.4
+ColorTypes 0.6.3
 FixedPointNumbers 0.3.0
 StatsBase 0.8.2
 Compat 0.18.0
diff --git a/src/ColorVectorSpace.jl b/src/ColorVectorSpace.jl
index 467f46b..ae5035d 100644
--- a/src/ColorVectorSpace.jl
+++ b/src/ColorVectorSpace.jl
@@ -264,14 +264,10 @@ norm(c::TransparentGray) = sqrt(abs2(c))
 isless(g1::AbstractGray, g2::AbstractGray) = isless(gray(g1), gray(g2))
 isless(c::AbstractGray, r::Real) = isless(gray(c), r)
 isless(r::Real, c::AbstractGray) = isless(r, gray(c))
-Base.isapprox(x::AbstractGray, y::AbstractGray; kwargs...) = isapprox(gray(x), gray(y); kwargs...)
-Base.isapprox(x::TransparentGray, y::TransparentGray; kwargs...) = isapprox(gray(x), gray(y); kwargs...) && isapprox(alpha(x), alpha(y); kwargs...)
-Base.isapprox(x::AbstractRGB, y::AbstractRGB; kwargs...) = isapprox(red(x), red(y); kwargs...) && isapprox(green(x), green(y); kwargs...) && isapprox(blue(x), blue(y); kwargs...)
-Base.isapprox(x::TransparentRGB, y::TransparentRGB; kwargs...) = isapprox(alpha(x), alpha(y); kwargs...) && isapprox(red(x), red(y); kwargs...) && isapprox(green(x), green(y); kwargs...) && isapprox(blue(x), blue(y); kwargs...)
 
 function Base.isapprox{Cx<:MathTypes,Cy<:MathTypes}(x::AbstractArray{Cx},
                                                     y::AbstractArray{Cy};
-                                                    rtol::Real=Base.rtoldefault(eltype(Cx),eltype(Cy)),
+                                                    rtol::Real=Base.rtoldefault(eltype(Cx),eltype(Cy),0),
                                                     atol::Real=0,
                                                     norm::Function=vecnorm)
     d = norm(x - y)
diff --git a/test/runtests.jl b/test/runtests.jl
index ce339d6..b35c8ff 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -112,7 +112,7 @@ end
         @test isapprox(a, a)
         @test real(Gray{Float32}) <: Real
         @test zero(ColorTypes.Gray) == 0
-        @test one(ColorTypes.Gray) == 1
+        @test oneunit(ColorTypes.Gray) == 1
         a = Gray{N0f8}[0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0]
         @test StatsBase.histrange(a,10) == 0.1f0:0.1f0:1f0